diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4c60f4502..1a1aa6618 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.12']
 
     services:
       postgres:
@@ -23,15 +23,15 @@ jobs:
         options: --health-cmd pg_isready --health-interval 5s --health-timeout 5s --health-retries 10
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 
       - name: Setup Node
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: 16.x
 
@@ -60,4 +60,4 @@ jobs:
 
       - name: Lint
         if: matrix.python-version == 3.12
-        run: make lint
+        run: make lint-ci
diff --git a/.gitignore b/.gitignore
index 828505958..91429c35c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,7 @@ __pycache__/
 *.whl
 build/
 .cache/
+.ruff_cache/
 pip-wheel-metadata/
 
 # Tests
diff --git a/.isort.cfg b/.isort.cfg
deleted file mode 100644
index 56c3731c1..000000000
--- a/.isort.cfg
+++ /dev/null
@@ -1,9 +0,0 @@
-[isort]
-multi_line_output=3
-include_trailing_comma=True
-force_grid_wrap=0
-use_parentheses=True
-line_length=88
-lines_after_imports=2
-skip=newdle/client/node_modules
-known_third_party=exchangelib
diff --git a/Makefile b/Makefile
index d40edaf3f..3f563b53c 100644
--- a/Makefile
+++ b/Makefile
@@ -94,19 +94,26 @@ react-server: i18n
 .PHONY: lint
 lint:
 	@printf "  \033[38;5;154mDEV\033[0m  \033[38;5;77mLinting code\033[0m\n"
-	@npm run flake8
+	@npm run ruff
 	@npm run eslint:check
 	@npm run prettier:check
-	@npm run isort:check
-	@npm run black:check
+	@npm run ruff-format:check
+
+
+.PHONY: lint-ci
+lint-ci:
+	@printf "  \033[38;5;154mDEV\033[0m  \033[38;5;77mLinting code (CI)\033[0m\n"
+	@npm run ruff -- --output-format github
+	@npm run eslint:check
+	@npm run prettier:check
+	@npm run ruff-format:check
 
 
 .PHONY: format
 format:
 	@printf "  \033[38;5;154mDEV\033[0m  \033[38;5;77mFormatting code\033[0m\n"
 	@npm run eslint
-	@npm run isort
-	@npm run black
+	@npm run ruff-format
 
 
 .PHONY: test
diff --git a/README.md b/README.md
index 0e7614889..89a9dff16 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ decided (still work in progress!).
 
 ## Development
 
-We chose Python 3.12 as the backend language, so make sure you have it installed (3.9-3.11 should work as well). To prepare the development environment it is enough to run `make` which takes care of installing all required dependencies inside a new virtualenv. Typically that will be the `.venv` directory unless you override the environment variable `VENV` *e.g.* `VENV=.virtualenv make`. Activate your virtualenv using ``source .venv/bin/activate`` since this is required to run the various `flask` comments that come later.
+We chose Python 3.12 as the backend language, so make sure you have it installed (`pyenv` helps if your distribution does not include it). To prepare the development environment it is enough to run `make` which takes care of installing all required dependencies inside a new virtualenv. Typically that will be the `.venv` directory unless you override the environment variable `VENV` *e.g.* `VENV=.virtualenv make`. Activate your virtualenv using ``source .venv/bin/activate`` since this is required to run the various `flask` comments that come later.
 
 Make sure you have the `python` binary in your PATH. You can also use the `PYTHON` environment variable to override the location of the
 `python` binary. *e.g.:*
@@ -64,7 +64,7 @@ We provide a couple of additional `make` targets that should streamline the deve
  - `make clean` - removes all generated files
  - `make distclean` - runs `clean` target first and removes config files afterwards
  - `make lint` - runs linters, which report possible code style issues
- - `make format` - runs code formatters over the entire codebase (black, isort, prettier)
+ - `make format` - runs code formatters over the entire codebase (ruff, prettier)
  - `make test` - runs Python and React tests
  - `make build` - builds a Python wheel which then could be used to install `newdle` in production
 
diff --git a/ci/check_history_consistency.py b/ci/check_history_consistency.py
index 92a3256db..130aa2615 100755
--- a/ci/check_history_consistency.py
+++ b/ci/check_history_consistency.py
@@ -3,6 +3,7 @@
 Checks the consistency of the history, by comparing flask db
 output and the filesystem ordering of files.
 """
+
 import re
 import subprocess
 import sys
@@ -37,7 +38,7 @@ def _check_history_consistency():
     if revisions != file_revisions:
         print(
             '::error::'
-            'The order of revisions in the database and in the filesystem is different. '
+            'The order of revisions in the database and filesystem is different. '
             'Please review them and make sure the revision history is linear. '
             'Make sure that all the migrations have a distinct "down_revision".'
         )
diff --git a/conftest.py b/conftest.py
index 0a19a4633..2eeb8cf0a 100644
--- a/conftest.py
+++ b/conftest.py
@@ -9,7 +9,6 @@
 from newdle.core.db import db
 from newdle.models import Newdle, Participant
 
-
 TEST_DATABASE_URI = os.environ.get(
     'NEWDLE_TEST_DATABASE_URI', 'postgresql:///newdle_tests'
 )
@@ -39,13 +38,13 @@ def database(app):
     flask_migrate.downgrade(revision='base')
 
 
-@pytest.fixture()
+@pytest.fixture
 def db_session(app, database):
     """Create a new database session."""
     connection = db.engine.connect()
     transaction = connection.begin()
 
-    options = dict(bind=connection, binds={})
+    options = {'bind': connection, 'binds': {}}
     session_factory = sessionmaker(**options)
     session = scoped_session(session_factory)
 
@@ -67,7 +66,7 @@ def mail_queue():
     return django_mail.outbox
 
 
-@pytest.fixture()
+@pytest.fixture
 def flask_client(app):
     return app.test_client()
 
@@ -89,7 +88,7 @@ def dummy_participant_uid():
 
 @pytest.fixture
 def create_newdle(dummy_uid, db_session):
-    """Return a callable which lets you create dummy newdles"""
+    """Return a callable which lets you create dummy newdles."""
 
     def _create_newdle(id=None, **kwargs):
         kwargs.setdefault(
diff --git a/newdle/api.py b/newdle/api.py
index 6a404a1ad..80d40334d 100644
--- a/newdle/api.py
+++ b/newdle/api.py
@@ -22,26 +22,26 @@
 from sqlalchemy.orm import selectinload
 from werkzeug.exceptions import Forbidden, ServiceUnavailable, UnprocessableEntity
 
-from .answers import validate_answers
-from .calendar import create_calendar_event
-from .core.auth import search_users, user_info_from_app_token
-from .core.db import db
-from .core.util import (
+from newdle.answers import validate_answers
+from newdle.calendar import create_calendar_event
+from newdle.core.auth import search_users, user_info_from_app_token
+from newdle.core.db import db
+from newdle.core.util import (
     DATE_FORMAT,
     avatar_info_from_payload,
     change_dt_timezone,
     range_union,
     render_user_avatar,
 )
-from .core.webargs import abort, use_args, use_kwargs
-from .export import export_answers_to_csv, export_answers_to_xlsx
-from .models import Availability, Newdle, Participant, StatKey, Stats
-from .notifications import (
+from newdle.core.webargs import abort, use_args, use_kwargs
+from newdle.export import export_answers_to_csv, export_answers_to_xlsx
+from newdle.models import Availability, Newdle, Participant, StatKey, Stats
+from newdle.notifications import (
     notify_newdle_creator,
     notify_newdle_participants,
     send_invitation_emails,
 )
-from .schemas import (
+from newdle.schemas import (
     DeletedNewdleSchema,
     MyNewdleSchema,
     NewdleParticipantSchema,
@@ -57,7 +57,6 @@
     UserSearchResultSchema,
 )
 
-
 api = Blueprint('api', __name__, url_prefix='/api')
 
 
@@ -616,7 +615,7 @@ def send_deletion_emails(args, code):
             'title': newdle.title,
             'participant': p.name,
             'summary_link': url_for('newdle_summary', code=newdle.code, _external=True),
-            'comment': args['comment'] if 'comment' in args else None,
+            'comment': args.get('comment'),
         },
     )
     return '', 204
diff --git a/newdle/auth.py b/newdle/auth.py
index aae77f6d6..ea2636e74 100644
--- a/newdle/auth.py
+++ b/newdle/auth.py
@@ -1,7 +1,6 @@
 from flask import Blueprint, current_app, redirect, render_template, session, url_for
 
-from .core.auth import app_token_from_dummy, multipass
-
+from newdle.core.auth import app_token_from_dummy, multipass
 
 auth = Blueprint('auth', __name__)
 
diff --git a/newdle/calendar.py b/newdle/calendar.py
index bdceca6b1..45361f20e 100644
--- a/newdle/calendar.py
+++ b/newdle/calendar.py
@@ -12,7 +12,7 @@ def _email_to_vcal_address(email):
 
 
 def _add_participant_to_ical_event(event, participant):
-    """Adds a participant as an attendee to an ical event."""
+    """Add a participant as an attendee to an ical event."""
     attendee = _email_to_vcal_address(participant.email)
     attendee.params['cn'] = vText(participant.name)
     attendee.params['ROLE'] = vText('REQ-PARTICIPANT')
@@ -47,8 +47,8 @@ def create_calendar_event(newdle, participant=None):
 
     if not newdle.private and not participant:
         participants = [p for p in newdle.participants if p.email]
-        for participant in participants:
-            _add_participant_to_ical_event(event, participant)
+        for part in participants:
+            _add_participant_to_ical_event(event, part)
 
     calendar.add_component(event)
     return calendar.to_ical()
diff --git a/newdle/cli.py b/newdle/cli.py
index f3c1b42c6..ed4358158 100644
--- a/newdle/cli.py
+++ b/newdle/cli.py
@@ -5,10 +5,13 @@
 from flask import Blueprint, current_app
 from sqlalchemy import and_, or_
 
-from .core.db import db
-from .models import Newdle
-from .providers.free_busy.util import get_msal_app, get_msal_token, save_msal_cache
-
+from newdle.core.db import db
+from newdle.models import Newdle
+from newdle.providers.free_busy.util import (
+    get_msal_app,
+    get_msal_token,
+    save_msal_cache,
+)
 
 try:
     import exchangelib
diff --git a/newdle/core/app.py b/newdle/core/app.py
index 6811c072c..493905a75 100644
--- a/newdle/core/app.py
+++ b/newdle/core/app.py
@@ -4,14 +4,14 @@
 from werkzeug.exceptions import HTTPException
 from werkzeug.middleware.proxy_fix import ProxyFix
 
-from ..api import api
-from ..auth import auth
-from ..cli import cli
-from .auth import multipass
-from .cache import cache
-from .db import db, migrate
-from .marshmallow import mm
-from .util import dedent
+from newdle.api import api
+from newdle.auth import auth
+from newdle.cli import cli
+from newdle.core.auth import multipass
+from newdle.core.cache import cache
+from newdle.core.db import db, migrate
+from newdle.core.marshmallow import mm
+from newdle.core.util import dedent
 
 
 def _configure_app(app, from_env=True):
@@ -76,7 +76,7 @@ def _handle_exception(exc):
             # If the client prefers HTML (probably a browser), we keep the
             # default logic which results in standard "internal server error"
             # message or the debugger while in development mode.
-            raise
+            raise  # noqa: PLE0704
         app.logger.exception('Request failed')
         return jsonify(error='internal_error'), 500
 
diff --git a/newdle/core/auth.py b/newdle/core/auth.py
index 50f06ba01..9fa590ccc 100644
--- a/newdle/core/auth.py
+++ b/newdle/core/auth.py
@@ -1,7 +1,7 @@
 from flask import current_app, render_template
 from flask_multipass import Multipass
 
-from .util import secure_timed_serializer
+from newdle.core.util import secure_timed_serializer
 
 
 class NewdleMultipass(Multipass):
diff --git a/newdle/core/cache.py b/newdle/core/cache.py
index 6a26d6190..9d828e39f 100644
--- a/newdle/core/cache.py
+++ b/newdle/core/cache.py
@@ -1,4 +1,3 @@
 from flask_caching import Cache
 
-
 cache = Cache(with_jinja2_ext=False)
diff --git a/newdle/core/marshmallow.py b/newdle/core/marshmallow.py
index 60475d74d..1127bd356 100644
--- a/newdle/core/marshmallow.py
+++ b/newdle/core/marshmallow.py
@@ -1,4 +1,3 @@
 from flask_marshmallow import Marshmallow
 
-
 mm = Marshmallow()
diff --git a/newdle/core/util.py b/newdle/core/util.py
index fe4b3405b..9de6d240a 100644
--- a/newdle/core/util.py
+++ b/newdle/core/util.py
@@ -7,7 +7,6 @@
 from itsdangerous import BadData, Signer, URLSafeSerializer, URLSafeTimedSerializer
 from werkzeug.local import LocalProxy
 
-
 DATE_FORMAT = '%Y-%m-%d'
 DATETIME_FORMAT = '%Y-%m-%dT%H:%M'
 
@@ -21,6 +20,7 @@
 
 
 class AutoNameEnum(Enum):
+    @staticmethod
     def _generate_next_value_(name, start, count, last_values):
         return name
 
diff --git a/newdle/core/webargs.py b/newdle/core/webargs.py
index 5de6b9d54..1d051d37d 100644
--- a/newdle/core/webargs.py
+++ b/newdle/core/webargs.py
@@ -28,9 +28,9 @@ def pre_load(self, location_data, *, schema, req, location):
 def handle_error(error, req, schema, *, error_status_code, error_headers):
     # since 6.0.0b7 errors are namespaced by their source. this is nice for APIs taking
     # data from different locations to serve very specific errors, but in a typical web
-    # app where you usually have only one source and certainly not the same field name in
-    # different locations, it just makes handling errors in JS harder since we suddenly
-    # have to care if it's form data or json data
+    # app where you usually have only one source and certainly not the same field name
+    # in different locations, it just makes handling errors in JS harder since we
+    # suddenly have to care if it's form data or json data
     namespaced = error.messages  # mutating this below is safe
     error.messages = namespaced.popitem()[1]
     assert not namespaced  # we never expect to have more than one location
diff --git a/newdle/export.py b/newdle/export.py
index 1a7b0ca4f..f1fff2c35 100644
--- a/newdle/export.py
+++ b/newdle/export.py
@@ -2,6 +2,7 @@
 import datetime
 from contextlib import contextmanager
 from io import BytesIO, TextIOWrapper
+from operator import itemgetter
 
 from xlsxwriter import Workbook
 
@@ -11,7 +12,7 @@
 def _generate_answers_for_export(newdle):
     slots = [format_dt(slot) for slot in newdle.timeslots]
     rows = []
-    rows.append(['Participant name'] + slots + ['Comment'])
+    rows.append(['Participant name', *slots, 'Comment'])
 
     for p in newdle.participants:
         answers = [p.name]
@@ -23,7 +24,7 @@ def _generate_answers_for_export(newdle):
         answers.append(p.comment)
         rows.append(answers)
     # Sort participants by name
-    rows[1:] = sorted(rows[1:], key=lambda row: row[0])
+    rows[1:] = sorted(rows[1:], key=itemgetter(0))
     return rows
 
 
diff --git a/newdle/migrations/env.py b/newdle/migrations/env.py
index d5900aaba..9f1831f7c 100644
--- a/newdle/migrations/env.py
+++ b/newdle/migrations/env.py
@@ -4,7 +4,6 @@
 from flask import current_app
 from sqlalchemy import engine_from_config, pool
 
-
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
 config = context.config
diff --git a/newdle/migrations/versions/20190912_1718_000000000000_create_initial_tables.py b/newdle/migrations/versions/20190912_1718_000000000000_create_initial_tables.py
index f825e6620..5b6933cc9 100644
--- a/newdle/migrations/versions/20190912_1718_000000000000_create_initial_tables.py
+++ b/newdle/migrations/versions/20190912_1718_000000000000_create_initial_tables.py
@@ -8,7 +8,6 @@
 from alembic import op
 from sqlalchemy.dialects import postgresql
 
-
 # revision identifiers, used by Alembic.
 revision = '000000000000'
 down_revision = None
diff --git a/newdle/migrations/versions/20200814_1707_93a638b96375_add_private_column_to_newdle_model.py b/newdle/migrations/versions/20200814_1707_93a638b96375_add_private_column_to_newdle_model.py
index 9491dd515..a8edf4d0e 100644
--- a/newdle/migrations/versions/20200814_1707_93a638b96375_add_private_column_to_newdle_model.py
+++ b/newdle/migrations/versions/20200814_1707_93a638b96375_add_private_column_to_newdle_model.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = '93a638b96375'
 down_revision = '000000000000'
diff --git a/newdle/migrations/versions/20200914_1149_679eab4aab01_add_comment_column_to_participants.py b/newdle/migrations/versions/20200914_1149_679eab4aab01_add_comment_column_to_participants.py
index 3a1bc8a24..2bd51106a 100644
--- a/newdle/migrations/versions/20200914_1149_679eab4aab01_add_comment_column_to_participants.py
+++ b/newdle/migrations/versions/20200914_1149_679eab4aab01_add_comment_column_to_participants.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = '679eab4aab01'
 down_revision = '93a638b96375'
diff --git a/newdle/migrations/versions/20200915_1105_239d7862e2fe_add_last_update_field_to_newdle_model.py b/newdle/migrations/versions/20200915_1105_239d7862e2fe_add_last_update_field_to_newdle_model.py
index f0271ca9d..ed7d3b246 100644
--- a/newdle/migrations/versions/20200915_1105_239d7862e2fe_add_last_update_field_to_newdle_model.py
+++ b/newdle/migrations/versions/20200915_1105_239d7862e2fe_add_last_update_field_to_newdle_model.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = '239d7862e2fe'
 down_revision = '679eab4aab01'
@@ -27,11 +26,11 @@ def upgrade():
         ),
     )
     op.execute(
-        '''
+        """
         UPDATE newdles
         SET last_update = final_dt
         WHERE final_dt IS NOT NULL AND final_dt < now() AT TIME ZONE 'utc';
-        '''
+        """
     )
 
 
diff --git a/newdle/migrations/versions/20200922_1759_43f0bf77bf97_add_newdle_creator_email_notify.py b/newdle/migrations/versions/20200922_1759_43f0bf77bf97_add_newdle_creator_email_notify.py
index f83e33bcc..0e54e4ff7 100644
--- a/newdle/migrations/versions/20200922_1759_43f0bf77bf97_add_newdle_creator_email_notify.py
+++ b/newdle/migrations/versions/20200922_1759_43f0bf77bf97_add_newdle_creator_email_notify.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = '43f0bf77bf97'
 down_revision = '239d7862e2fe'
diff --git a/newdle/migrations/versions/20200928_1154_d85e02075214_add_newdle_deletion_date.py b/newdle/migrations/versions/20200928_1154_d85e02075214_add_newdle_deletion_date.py
index 6e146691d..537a6992a 100644
--- a/newdle/migrations/versions/20200928_1154_d85e02075214_add_newdle_deletion_date.py
+++ b/newdle/migrations/versions/20200928_1154_d85e02075214_add_newdle_deletion_date.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = 'd85e02075214'
 down_revision = '43f0bf77bf97'
diff --git a/newdle/migrations/versions/20210531_1656_28103ebec68e_add_stats_table.py b/newdle/migrations/versions/20210531_1656_28103ebec68e_add_stats_table.py
index 1d109132f..377afd04b 100644
--- a/newdle/migrations/versions/20210531_1656_28103ebec68e_add_stats_table.py
+++ b/newdle/migrations/versions/20210531_1656_28103ebec68e_add_stats_table.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = '28103ebec68e'
 down_revision = 'd85e02075214'
@@ -24,13 +23,13 @@ def upgrade():
         sa.PrimaryKeyConstraint('key', name=op.f('pk_stats')),
     )
     op.execute(
-        '''
+        """
         INSERT INTO stats (key, value)
         SELECT 'newdles_created', COUNT(*) FROM newdles;
 
         INSERT INTO stats (key, value)
         SELECT 'participants_created', COUNT(*) FROM participants;
-        '''
+        """
     )
 
 
diff --git a/newdle/migrations/versions/20220429_0945_30b5fe7b5949_add_limited_slots.py b/newdle/migrations/versions/20220429_0945_30b5fe7b5949_add_limited_slots.py
index f8132db12..920d34afd 100644
--- a/newdle/migrations/versions/20220429_0945_30b5fe7b5949_add_limited_slots.py
+++ b/newdle/migrations/versions/20220429_0945_30b5fe7b5949_add_limited_slots.py
@@ -8,7 +8,6 @@
 import sqlalchemy as sa
 from alembic import op
 
-
 # revision identifiers, used by Alembic.
 revision = '30b5fe7b5949'
 down_revision = '28103ebec68e'
diff --git a/newdle/models.py b/newdle/models.py
index 526085869..ab8a2292e 100644
--- a/newdle/models.py
+++ b/newdle/models.py
@@ -8,9 +8,8 @@
 from sqlalchemy.ext.hybrid import hybrid_property
 from sqlalchemy.schema import CheckConstraint
 
-from .core.db import db
-from .core.util import AutoNameEnum, format_dt, parse_dt
-
+from newdle.core.db import db
+from newdle.core.util import AutoNameEnum, format_dt, parse_dt
 
 CODE_ALPHABET = '23456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ'
 
@@ -158,7 +157,7 @@ def answers(self, value):
 
     def __repr__(self):
         return '<Participant {}: {}{}>'.format(
-            self.id, self.name, ' ({})'.format(self.email) if self.email else ''
+            self.id, self.name, f' ({self.email})' if self.email else ''
         )
 
 
diff --git a/newdle/notifications.py b/newdle/notifications.py
index 8f51bbe8c..229002df0 100644
--- a/newdle/notifications.py
+++ b/newdle/notifications.py
@@ -1,7 +1,7 @@
 from flask import current_app, g, render_template, url_for
 
-from .vendor.django_mail import get_connection
-from .vendor.django_mail.message import EmailMultiAlternatives
+from newdle.vendor.django_mail import get_connection
+from newdle.vendor.django_mail.message import EmailMultiAlternatives
 
 
 def send_invitation_emails(newdle, participants=None):
diff --git a/newdle/providers/free_busy/exchange.py b/newdle/providers/free_busy/exchange.py
index 640c151fa..982e0315a 100644
--- a/newdle/providers/free_busy/exchange.py
+++ b/newdle/providers/free_busy/exchange.py
@@ -19,9 +19,8 @@
 from oauthlib.oauth2.rfc6749.tokens import OAuth2Token
 from werkzeug.exceptions import ServiceUnavailable
 
-from ...core.util import find_overlap
-from .util import get_msal_token
-
+from newdle.core.util import find_overlap
+from newdle.providers.free_busy.util import get_msal_token
 
 TYPE_MAP = {'Busy': 'busy', 'Tentative': 'busy', 'OOF': 'busy'}
 
diff --git a/newdle/providers/free_busy/ox.py b/newdle/providers/free_busy/ox.py
index 0470f1442..c39fa7d1e 100644
--- a/newdle/providers/free_busy/ox.py
+++ b/newdle/providers/free_busy/ox.py
@@ -6,7 +6,7 @@
 from flask import current_app
 from requests.models import HTTPBasicAuth
 
-from ...core.util import find_overlap
+from newdle.core.util import find_overlap
 
 
 def fetch_free_busy(date, tz, uid, email):
@@ -52,10 +52,10 @@ def fetch_free_busy(date, tz, uid, email):
         # this includes BUSY, BUSY-UNAVAILABLE and BUSY-TENTATIVE
         if line.startswith('FREEBUSY;FBTYPE=BUSY'):
             try:
-                start_dt, end_dt = [
+                start_dt, end_dt = (
                     datetime.strptime(dt, '%Y%m%dT%H%M%S%z')
                     for dt in line.split(':')[1].split('/')
-                ]
+                )
             except IndexError:
                 continue
 
diff --git a/newdle/providers/free_busy/random.py b/newdle/providers/free_busy/random.py
index 80e1dadfb..a342a8566 100644
--- a/newdle/providers/free_busy/random.py
+++ b/newdle/providers/free_busy/random.py
@@ -4,7 +4,7 @@
 
 import pytz
 
-from ...core.util import find_overlap
+from newdle.core.util import find_overlap
 
 
 def fetch_free_busy(date, tz, uid, email):
diff --git a/newdle/providers/free_busy/util.py b/newdle/providers/free_busy/util.py
index 2325eaeaf..3d783970c 100644
--- a/newdle/providers/free_busy/util.py
+++ b/newdle/providers/free_busy/util.py
@@ -2,7 +2,6 @@
 
 from flask import current_app
 
-
 try:
     from msal import PublicClientApplication, SerializableTokenCache
 
diff --git a/newdle/schemas.py b/newdle/schemas.py
index d1f02819a..6b9f4a0e0 100644
--- a/newdle/schemas.py
+++ b/newdle/schemas.py
@@ -12,15 +12,15 @@
 from marshmallow_enum import EnumField
 from pytz import common_timezones_set
 
-from .core.marshmallow import mm
-from .core.util import (
+from newdle.core.marshmallow import mm
+from newdle.core.util import (
     DATETIME_FORMAT,
     avatar_payload_from_participant,
     avatar_payload_from_user_info,
     check_user_signature,
     sign_user,
 )
-from .models import Availability
+from newdle.models import Availability
 
 
 class UserSchema(mm.Schema):
diff --git a/newdle/vendor/django_mail/__init__.py b/newdle/vendor/django_mail/__init__.py
index 2dd662ab2..bd3cf23e6 100644
--- a/newdle/vendor/django_mail/__init__.py
+++ b/newdle/vendor/django_mail/__init__.py
@@ -4,7 +4,7 @@
 # The code in here is taken almost verbatim from `django.core.mail`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/2.2.x/django/core/mail/__init__.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/__init__.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
@@ -16,7 +16,6 @@
 from .backends.base import BaseEmailBackend
 from .module_loading_utils import import_string
 
-
 __all__ = ['get_connection']
 
 
diff --git a/newdle/vendor/django_mail/backends/base.py b/newdle/vendor/django_mail/backends/base.py
index d9d504de8..6668a6da6 100644
--- a/newdle/vendor/django_mail/backends/base.py
+++ b/newdle/vendor/django_mail/backends/base.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.core.mail.backends.base`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/core/mail/backends/base.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/backends/base.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
diff --git a/newdle/vendor/django_mail/backends/console.py b/newdle/vendor/django_mail/backends/console.py
index ddd002597..5f98593e5 100644
--- a/newdle/vendor/django_mail/backends/console.py
+++ b/newdle/vendor/django_mail/backends/console.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.core.mail.backends.console`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/core/mail/backends/console.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/backends/console.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
diff --git a/newdle/vendor/django_mail/backends/locmem.py b/newdle/vendor/django_mail/backends/locmem.py
index 5279f6995..e6eb5515c 100644
--- a/newdle/vendor/django_mail/backends/locmem.py
+++ b/newdle/vendor/django_mail/backends/locmem.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.core.mail.backends.locmem`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/core/mail/backends/locmem.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/backends/locmem.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
@@ -9,6 +9,8 @@
 Backend for test environment.
 """
 
+import copy
+
 from newdle.vendor import django_mail
 
 from .base import BaseEmailBackend
@@ -34,6 +36,6 @@ def send_messages(self, messages):
         msg_count = 0
         for message in messages:  # .message() triggers header validation
             message.message()
-            django_mail.outbox.append(message)
+            django_mail.outbox.append(copy.deepcopy(message))
             msg_count += 1
         return msg_count
diff --git a/newdle/vendor/django_mail/backends/smtp.py b/newdle/vendor/django_mail/backends/smtp.py
index ae21bd7e0..e6191ed36 100644
--- a/newdle/vendor/django_mail/backends/smtp.py
+++ b/newdle/vendor/django_mail/backends/smtp.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.core.mail.backends.smtp`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/core/mail/backends/smtp.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/backends/smtp.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
@@ -11,6 +11,7 @@
 import threading
 
 from flask import current_app
+from werkzeug.utils import cached_property
 
 from ..encoding_utils import DEFAULT_CHARSET
 from ..message import sanitize_address
@@ -67,8 +68,8 @@ def __init__(
         )
         if self.use_ssl and self.use_tls:
             raise ValueError(
-                "EMAIL_USE_TLS/EMAIL_USE_SSL are mutually exclusive, so only set "
-                "one of those settings to True."
+                'EMAIL_USE_TLS/EMAIL_USE_SSL are mutually exclusive, so only set '
+                'one of those settings to True.'
             )
         self.connection = None
         self._lock = threading.RLock()
@@ -77,6 +78,15 @@ def __init__(
     def connection_class(self):
         return smtplib.SMTP_SSL if self.use_ssl else smtplib.SMTP
 
+    @cached_property
+    def ssl_context(self):
+        if self.ssl_certfile or self.ssl_keyfile:
+            ssl_context = ssl.SSLContext(protocol=ssl.PROTOCOL_TLS_CLIENT)
+            ssl_context.load_cert_chain(self.ssl_certfile, self.ssl_keyfile)
+            return ssl_context
+        else:
+            return ssl.create_default_context()
+
     def open(self):
         """
         Ensure an open connection to the email server. Return whether or not a
@@ -93,9 +103,7 @@ def open(self):
         if self.timeout is not None:
             connection_params['timeout'] = self.timeout
         if self.use_ssl:
-            connection_params.update(
-                {'keyfile': self.ssl_keyfile, 'certfile': self.ssl_certfile}
-            )
+            connection_params['context'] = self.ssl_context
         try:
             self.connection = self.connection_class(
                 self.host, self.port, **connection_params
@@ -104,9 +112,7 @@ def open(self):
             # TLS/SSL are mutually exclusive, so only attempt TLS over
             # non-secure connections.
             if not self.use_ssl and self.use_tls:
-                self.connection.starttls(
-                    keyfile=self.ssl_keyfile, certfile=self.ssl_certfile
-                )
+                self.connection.starttls(context=self.ssl_context)
             if self.username and self.password:
                 self.connection.login(self.username, self.password)
             return True
@@ -147,12 +153,14 @@ def send_messages(self, email_messages):
                 # Trying to send would be pointless.
                 return 0
             num_sent = 0
-            for message in email_messages:
-                sent = self._send(message)
-                if sent:
-                    num_sent += 1
-            if new_conn_created:
-                self.close()
+            try:
+                for message in email_messages:
+                    sent = self._send(message)
+                    if sent:
+                        num_sent += 1
+            finally:
+                if new_conn_created:
+                    self.close()
         return num_sent
 
     def _send(self, email_message):
diff --git a/newdle/vendor/django_mail/encoding_utils.py b/newdle/vendor/django_mail/encoding_utils.py
index 8a18fd14c..f6e486ed1 100644
--- a/newdle/vendor/django_mail/encoding_utils.py
+++ b/newdle/vendor/django_mail/encoding_utils.py
@@ -1,33 +1,28 @@
 # The code in here is taken almost verbatim from `django.utils.encoding`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/utils/encoding.py
+# https://github.com/django/django/blob/425b26092f/django/utils/encoding.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
-
 import datetime
 from decimal import Decimal
-
+from types import NoneType
 
 DEFAULT_CHARSET = 'utf-8'
 
 
 class DjangoUnicodeDecodeError(UnicodeDecodeError):
-    def __init__(self, obj, *args):
-        self.obj = obj
-        super().__init__(*args)
-
     def __str__(self):
         return '%s. You passed in %r (%s)' % (
             super().__str__(),
-            self.obj,
-            type(self.obj),
+            self.object,
+            type(self.object),
         )
 
 
 _PROTECTED_TYPES = (
-    type(None),
+    NoneType,
     int,
     float,
     Decimal,
@@ -41,7 +36,7 @@ def is_protected_type(obj):
     """Determine if the object instance is of a protected type.
 
     Objects of protected types are preserved as-is when passed to
-    force_text(strings_only=True).
+    force_str(strings_only=True).
     """
     return isinstance(obj, _PROTECTED_TYPES)
 
@@ -50,6 +45,7 @@ def force_str(s, encoding='utf-8', strings_only=False, errors='strict'):
     """
     Similar to smart_str(), except that lazy instances are resolved to
     strings, rather than kept as lazy objects.
+
     If strings_only is True, don't convert (some) non-string-like objects.
     """
     # Handle the common case first for performance reasons.
@@ -63,7 +59,7 @@ def force_str(s, encoding='utf-8', strings_only=False, errors='strict'):
         else:
             s = str(s)
     except UnicodeDecodeError as e:
-        raise DjangoUnicodeDecodeError(s, *e.args)
+        raise DjangoUnicodeDecodeError(*e.args) from None
     return s
 
 
diff --git a/newdle/vendor/django_mail/message.py b/newdle/vendor/django_mail/message.py
index 69b4a68db..f0b65cfcc 100644
--- a/newdle/vendor/django_mail/message.py
+++ b/newdle/vendor/django_mail/message.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.core.mail.message`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/core/mail/message.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/message.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
@@ -24,7 +24,6 @@
 from .encoding_utils import DEFAULT_CHARSET, force_str, punycode
 from .utils import DNS_NAME
 
-
 # Don't BASE64-encode UTF-8 messages so that we avoid unwanted attention from
 # some spam filters.
 utf8_charset = Charset.Charset('utf-8')
@@ -43,7 +42,7 @@ class BadHeaderError(ValueError):
     pass
 
 
-# Header names that contain structured address data (RFC #5322)
+# Header names that contain structured address data (RFC 5322).
 ADDRESS_HEADERS = {
     'from',
     'sender',
@@ -104,6 +103,8 @@ def sanitize_address(addr, encoding):
             domain = token.domain or ''
     else:
         nm, address = addr
+        if '@' not in address:
+            raise ValueError(f'Invalid address "{address}"')
         localpart, domain = address.rsplit('@', 1)
 
     address_parts = nm + localpart + domain
@@ -173,7 +174,8 @@ def __setitem__(self, name, val):
     def set_payload(self, payload, charset=None):
         if charset == 'utf-8' and not isinstance(charset, Charset.Charset):
             has_long_lines = any(
-                len(line.encode()) > RFC5322_EMAIL_LINE_LENGTH_LIMIT
+                len(line.encode(errors='surrogateescape'))
+                > RFC5322_EMAIL_LINE_LENGTH_LIMIT
                 for line in payload.splitlines()
             )
             # Quoted-Printable encoding has the side effect of shortening long
@@ -317,11 +319,15 @@ def attach(self, filename=None, content=None, mimetype=None):
         mimetype to DEFAULT_ATTACHMENT_MIME_TYPE and don't decode the content.
         """
         if isinstance(filename, MIMEBase):
-            assert content is None
-            assert mimetype is None
+            if content is not None or mimetype is not None:
+                raise ValueError(
+                    'content and mimetype must not be given when a MIMEBase '
+                    'instance is provided.'
+                )
             self.attachments.append(filename)
+        elif content is None:
+            raise ValueError('content must be provided.')
         else:
-            assert content is not None
             mimetype = (
                 mimetype
                 or mimetypes.guess_type(filename)[0]
@@ -385,8 +391,8 @@ def _create_mime_attachment(self, content, mimetype):
             encoding = self.encoding or DEFAULT_CHARSET
             attachment = SafeMIMEText(content, subtype, encoding)
         elif basetype == 'message' and subtype == 'rfc822':
-            # Bug #18967: per RFC2046 s5.2.1, message/rfc822 attachments
-            # must not be base64 encoded.
+            # Bug #18967: Per RFC 2046 Section 5.2.1, message/rfc822
+            # attachments must not be base64 encoded.
             if isinstance(content, EmailMessage):
                 # convert content into an email.Message first
                 content = content.message()
@@ -475,8 +481,8 @@ def __init__(
 
     def attach_alternative(self, content, mimetype):
         """Attach an alternative content representation."""
-        assert content is not None
-        assert mimetype is not None
+        if content is None or mimetype is None:
+            raise ValueError('Both content and mimetype must be provided.')
         self.alternatives.append((content, mimetype))
 
     def _create_message(self, msg):
diff --git a/newdle/vendor/django_mail/module_loading_utils.py b/newdle/vendor/django_mail/module_loading_utils.py
index aa3466057..2f58475e9 100644
--- a/newdle/vendor/django_mail/module_loading_utils.py
+++ b/newdle/vendor/django_mail/module_loading_utils.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.utils.module_loading`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/2.2.x/django/utils/module_loading.py
+# https://github.com/django/django/blob/425b26092f/django/utils/module_loading.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
diff --git a/newdle/vendor/django_mail/utils.py b/newdle/vendor/django_mail/utils.py
index 948c42445..3665e818b 100644
--- a/newdle/vendor/django_mail/utils.py
+++ b/newdle/vendor/django_mail/utils.py
@@ -1,7 +1,7 @@
 # The code in here is taken almost verbatim from `django.core.mail.utils`,
 # which is licensed under the three-clause BSD license and is originally
 # available on the following URL:
-# https://github.com/django/django/blob/stable/3.1.x/django/core/mail/utils.py
+# https://github.com/django/django/blob/425b26092f/django/core/mail/utils.py
 # Credits of the original code go to the Django Software Foundation
 # and their contributors.
 
diff --git a/newdle/wsgi.py b/newdle/wsgi.py
index 6dbd19dfb..83e1c552a 100644
--- a/newdle/wsgi.py
+++ b/newdle/wsgi.py
@@ -1,4 +1,3 @@
 from newdle.core.app import create_app
 
-
 app = create_app()
diff --git a/package.json b/package.json
index 97a550763..91b63857d 100644
--- a/package.json
+++ b/package.json
@@ -4,14 +4,12 @@
   "scripts": {
     "prettier": "prettier --write 'newdle/client/src/**/*.{js,jsx,json,scss,css}'",
     "prettier:check": "prettier --check 'newdle/client/src/**/*.{js,jsx,json,scss,css}'",
-    "isort": "isort setup.py conftest.py ci/ newdle/ tests/",
-    "isort:check": "npm run isort -- --diff --check-only",
-    "black": "black setup.py conftest.py ci/ newdle/ tests/",
-    "black:check": "npm run black -- --diff --check",
+    "ruff-format": "ruff format setup.py conftest.py ci/ newdle/ tests/",
+    "ruff-format:check": "npm run ruff-format -- --diff --check",
     "eslint": "cd newdle/client && npx eslint --fix --max-warnings 0 src/",
     "eslint:specific": "cd newdle/client && npx eslint --fix --max-warnings 0",
     "eslint:check": "cd newdle/client && npx eslint --max-warnings 0 src/",
-    "flake8": "flake8 conftest.py ci/ newdle/ tests/",
+    "ruff": "ruff check conftest.py ci/ newdle/ tests/",
     "pydeps:update": "pip-compile --strip-extras --resolver=backtracking -q -U && pip-compile --strip-extras --resolver=backtracking -q -U requirements.dev.in && pip-compile --strip-extras --resolver=backtracking -q -U requirements.exchange.in && pip-compile --strip-extras --resolver=backtracking -q -U requirements.cern.in",
     "pydeps:lock": "pip-compile --strip-extras --resolver=backtracking -q && pip-compile --strip-extras --resolver=backtracking -q requirements.dev.in && pip-compile --strip-extras --resolver=backtracking -q requirements.exchange.in && pip-compile --strip-extras --resolver=backtracking -q requirements.cern.in"
   },
@@ -25,8 +23,8 @@
       "git add newdle/client/src/locales/"
     ],
     "{newdle,tests,ci}/**/*.py": [
-      "isort",
-      "black"
+      "ruff check --fix",
+      "ruff format"
     ]
   },
   "husky": {
diff --git a/pyproject.toml b/pyproject.toml
deleted file mode 100644
index 209c6ec88..000000000
--- a/pyproject.toml
+++ /dev/null
@@ -1,21 +0,0 @@
-[tool.black]
-target_version = ['py39']
-skip-string-normalization = true
-exclude = '''
-(
-  /(
-      \.eggs         # exclude a few common directories in the
-    | \.git          # root of the project [black defaults]
-    | \.hg
-    | \.mypy_cache
-    | \.tox
-    | \.venv
-    | _build
-    | buck-out
-    | build
-    | dist
-  )/
-  | node_modules
-  | newdle/client/
-)
-'''
diff --git a/requirements.cern.txt b/requirements.cern.txt
index 4acb3e97d..7c31c8e87 100644
--- a/requirements.cern.txt
+++ b/requirements.cern.txt
@@ -1,19 +1,19 @@
 #
-# This file is autogenerated by pip-compile with Python 3.9
+# This file is autogenerated by pip-compile with Python 3.12
 # by the following command:
 #
 #    pip-compile --strip-extras requirements.cern.in
 #
-authlib==1.2.1
+authlib==1.3.0
     # via
     #   -c requirements.txt
     #   flask-multipass
-blinker==1.7.0
+blinker==1.8.2
     # via
     #   -c requirements.txt
     #   flask
     #   flask-multipass
-certifi==2023.7.22
+certifi==2024.2.2
     # via
     #   -c requirements.txt
     #   requests
@@ -29,43 +29,38 @@ click==8.1.7
     # via
     #   -c requirements.txt
     #   flask
-cryptography==41.0.6
+cryptography==42.0.7
     # via
     #   -c requirements.txt
     #   authlib
-flask==3.0.0
+flask==3.0.3
     # via
     #   -c requirements.txt
     #   flask-multipass
-flask-multipass==0.5.1
+flask-multipass==0.5.4
     # via
     #   -c requirements.txt
-    #   flask-multipass
     #   flask-multipass-cern
 flask-multipass-cern==2.2.9
     # via -r requirements.cern.in
-idna==3.4
+idna==3.7
     # via
     #   -c requirements.txt
     #   requests
-importlib-metadata==6.8.0
-    # via
-    #   -c requirements.txt
-    #   flask
-itsdangerous==2.1.2
+itsdangerous==2.2.0
     # via
     #   -c requirements.txt
     #   flask
-jinja2==3.1.3
+jinja2==3.1.4
     # via
     #   -c requirements.txt
     #   flask
-markupsafe==2.1.3
+markupsafe==2.1.5
     # via
     #   -c requirements.txt
     #   jinja2
     #   werkzeug
-pycparser==2.21
+pycparser==2.22
     # via
     #   -c requirements.txt
     #   cffi
@@ -73,16 +68,12 @@ requests==2.31.0
     # via
     #   -c requirements.txt
     #   flask-multipass
-urllib3==2.1.0
+urllib3==2.2.1
     # via
     #   -c requirements.txt
     #   flask-multipass-cern
     #   requests
-werkzeug==3.0.1
+werkzeug==3.0.3
     # via
     #   -c requirements.txt
     #   flask
-zipp==3.17.0
-    # via
-    #   -c requirements.txt
-    #   importlib-metadata
diff --git a/requirements.dev.in b/requirements.dev.in
index 53ef1996f..46164ca63 100644
--- a/requirements.dev.in
+++ b/requirements.dev.in
@@ -1,13 +1,10 @@
 -c requirements.txt
-black
-flake8
-flake8-quotes
 flask-shell-ipython
 ipython
-isort
 pip-tools
 pytest
 pytest-cov
 pytest-mock
 pytest-snapshot
+ruff
 wheel
diff --git a/requirements.dev.txt b/requirements.dev.txt
index 466be0df1..9a4659495 100644
--- a/requirements.dev.txt
+++ b/requirements.dev.txt
@@ -1,165 +1,117 @@
 #
-# This file is autogenerated by pip-compile with Python 3.9
+# This file is autogenerated by pip-compile with Python 3.12
 # by the following command:
 #
 #    pip-compile --strip-extras requirements.dev.in
 #
 asttokens==2.4.1
     # via stack-data
-black==23.11.0
-    # via -r requirements.dev.in
-blinker==1.7.0
+blinker==1.8.2
     # via
     #   -c requirements.txt
     #   flask
-build==1.0.3
+build==1.2.1
     # via pip-tools
 click==8.1.7
     # via
     #   -c requirements.txt
-    #   black
     #   flask
     #   flask-shell-ipython
     #   pip-tools
-coverage==7.3.2
-    # via
-    #   coverage
-    #   pytest-cov
+coverage==7.5.1
+    # via pytest-cov
 decorator==5.1.1
     # via ipython
-exceptiongroup==1.1.3
-    # via
-    #   ipython
-    #   pytest
 executing==2.0.1
     # via stack-data
-flake8==6.1.0
-    # via
-    #   -r requirements.dev.in
-    #   flake8-quotes
-flake8-quotes==3.3.2
-    # via -r requirements.dev.in
-flask==3.0.0
+flask==3.0.3
     # via
     #   -c requirements.txt
     #   flask-shell-ipython
 flask-shell-ipython==0.5.1
     # via -r requirements.dev.in
-importlib-metadata==6.8.0
-    # via
-    #   -c requirements.txt
-    #   build
-    #   flask
 iniconfig==2.0.0
     # via pytest
-ipython==8.17.2
+ipython==8.24.0
     # via
     #   -r requirements.dev.in
     #   flask-shell-ipython
-isort==5.12.0
-    # via -r requirements.dev.in
-itsdangerous==2.1.2
+itsdangerous==2.2.0
     # via
     #   -c requirements.txt
     #   flask
 jedi==0.19.1
     # via ipython
-jinja2==3.1.3
+jinja2==3.1.4
     # via
     #   -c requirements.txt
     #   flask
-markupsafe==2.1.3
+markupsafe==2.1.5
     # via
     #   -c requirements.txt
     #   jinja2
     #   werkzeug
-matplotlib-inline==0.1.6
+matplotlib-inline==0.1.7
     # via ipython
-mccabe==0.7.0
-    # via flake8
-mypy-extensions==1.0.0
-    # via black
-packaging==23.2
+packaging==24.0
     # via
     #   -c requirements.txt
-    #   black
     #   build
     #   pytest
-parso==0.8.3
+parso==0.8.4
     # via jedi
-pathspec==0.11.2
-    # via black
-pexpect==4.8.0
+pexpect==4.9.0
     # via ipython
-pip-tools==7.3.0
+pip-tools==7.4.1
     # via -r requirements.dev.in
-platformdirs==4.0.0
-    # via black
-pluggy==1.3.0
+pluggy==1.5.0
     # via pytest
-prompt-toolkit==3.0.41
+prompt-toolkit==3.0.43
     # via ipython
 ptyprocess==0.7.0
     # via pexpect
 pure-eval==0.2.2
     # via stack-data
-pycodestyle==2.11.1
-    # via flake8
-pyflakes==3.1.0
-    # via flake8
-pygments==2.16.1
+pygments==2.18.0
     # via ipython
-pyproject-hooks==1.0.0
-    # via build
-pytest==7.4.3
+pyproject-hooks==1.1.0
+    # via
+    #   build
+    #   pip-tools
+pytest==8.2.0
     # via
     #   -r requirements.dev.in
     #   pytest-cov
     #   pytest-mock
     #   pytest-snapshot
-pytest-cov==4.1.0
+pytest-cov==5.0.0
     # via -r requirements.dev.in
-pytest-mock==3.12.0
+pytest-mock==3.14.0
     # via -r requirements.dev.in
 pytest-snapshot==0.9.0
     # via -r requirements.dev.in
+ruff==0.4.3
+    # via -r requirements.dev.in
 six==1.16.0
     # via
     #   -c requirements.txt
     #   asttokens
 stack-data==0.6.3
     # via ipython
-tomli==2.0.1
-    # via
-    #   black
-    #   build
-    #   coverage
-    #   pip-tools
-    #   pyproject-hooks
-    #   pytest
-traitlets==5.13.0
+traitlets==5.14.3
     # via
     #   ipython
     #   matplotlib-inline
-typing-extensions==4.8.0
-    # via
-    #   -c requirements.txt
-    #   black
-    #   ipython
-wcwidth==0.2.10
+wcwidth==0.2.13
     # via prompt-toolkit
-werkzeug==3.0.1
+werkzeug==3.0.3
     # via
     #   -c requirements.txt
     #   flask
-wheel==0.41.3
+wheel==0.43.0
     # via
     #   -r requirements.dev.in
     #   pip-tools
-zipp==3.17.0
-    # via
-    #   -c requirements.txt
-    #   importlib-metadata
 
 # The following packages are considered to be unsafe in a requirements file:
 # pip
diff --git a/requirements.exchange.txt b/requirements.exchange.txt
index da4740499..8f5ae130a 100644
--- a/requirements.exchange.txt
+++ b/requirements.exchange.txt
@@ -1,12 +1,12 @@
 #
-# This file is autogenerated by pip-compile with Python 3.9
+# This file is autogenerated by pip-compile with Python 3.12
 # by the following command:
 #
 #    pip-compile --strip-extras requirements.exchange.in
 #
 cached-property==1.5.2
     # via exchangelib
-certifi==2023.7.22
+certifi==2024.2.2
     # via
     #   -c requirements.txt
     #   requests
@@ -18,7 +18,7 @@ charset-normalizer==3.3.2
     # via
     #   -c requirements.txt
     #   requests
-cryptography==41.0.6
+cryptography==42.0.7
     # via
     #   -c requirements.txt
     #   msal
@@ -27,29 +27,29 @@ cryptography==41.0.6
     #   requests-ntlm
 defusedxml==0.7.1
     # via exchangelib
-dnspython==2.4.2
+dnspython==2.6.1
     # via exchangelib
-exchangelib==5.1.0
+exchangelib==5.3.0
     # via -r requirements.exchange.in
-idna==3.4
+idna==3.7
     # via
     #   -c requirements.txt
     #   requests
 isodate==0.6.1
     # via exchangelib
-lxml==4.9.3
+lxml==5.2.1
     # via exchangelib
-msal==1.25.0
+msal==1.28.0
     # via -r requirements.exchange.in
 oauthlib==3.2.2
     # via
     #   exchangelib
     #   requests-oauthlib
-pycparser==2.21
+pycparser==2.22
     # via
     #   -c requirements.txt
     #   cffi
-pygments==2.16.1
+pygments==2.18.0
     # via exchangelib
 pyjwt==2.8.0
     # via
@@ -66,19 +66,19 @@ requests==2.31.0
     #   requests-oauthlib
 requests-ntlm==1.2.0
     # via exchangelib
-requests-oauthlib==1.3.1
+requests-oauthlib==2.0.0
     # via exchangelib
 six==1.16.0
     # via
     #   -c requirements.txt
     #   isodate
-tzdata==2023.3
+tzdata==2024.1
     # via exchangelib
 tzlocal==3.0
     # via
     #   -r requirements.exchange.in
     #   exchangelib
-urllib3==2.1.0
+urllib3==2.2.1
     # via
     #   -c requirements.txt
     #   requests
diff --git a/requirements.txt b/requirements.txt
index e0744618b..348254ae4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,22 +1,22 @@
 #
-# This file is autogenerated by pip-compile with Python 3.9
+# This file is autogenerated by pip-compile with Python 3.12
 # by the following command:
 #
 #    pip-compile --strip-extras
 #
-alembic==1.12.1
+alembic==1.13.1
     # via
     #   -r requirements.in
     #   flask-migrate
-authlib==1.2.1
+authlib==1.3.0
     # via flask-multipass
-blinker==1.7.0
+blinker==1.8.2
     # via
     #   flask
     #   flask-multipass
 cachelib==0.9.0
     # via flask-caching
-certifi==2023.7.22
+certifi==2024.2.2
     # via requests
 cffi==1.16.0
     # via cryptography
@@ -26,11 +26,11 @@ click==8.1.7
     # via
     #   flask
     #   flask-url-map-serializer
-cryptography==41.0.6
+cryptography==42.0.7
     # via authlib
-faker==20.0.3
+faker==25.0.1
     # via -r requirements.in
-flask==3.0.0
+flask==3.0.3
     # via
     #   -r requirements.in
     #   flask-caching
@@ -39,13 +39,13 @@ flask==3.0.0
     #   flask-multipass
     #   flask-sqlalchemy
     #   flask-url-map-serializer
-flask-caching==2.1.0
+flask-caching==2.3.0
     # via -r requirements.in
-flask-marshmallow==0.15.0
+flask-marshmallow==1.2.1
     # via -r requirements.in
-flask-migrate==4.0.5
+flask-migrate==4.0.7
     # via -r requirements.in
-flask-multipass==0.5.1
+flask-multipass==0.5.4
     # via -r requirements.in
 flask-sqlalchemy==3.1.1
     # via
@@ -53,30 +53,28 @@ flask-sqlalchemy==3.1.1
     #   flask-migrate
 flask-url-map-serializer==0.0.1
     # via -r requirements.in
-greenlet==3.0.1
+greenlet==3.0.3
     # via sqlalchemy
-icalendar==5.0.11
+icalendar==5.0.12
     # via -r requirements.in
-idna==3.4
+idna==3.7
     # via requests
-importlib-metadata==6.8.0
-    # via flask
-itsdangerous==2.1.2
+itsdangerous==2.2.0
     # via
     #   -r requirements.in
     #   flask
-jinja2==3.1.3
+jinja2==3.1.4
     # via
     #   -r requirements.in
     #   flask
-mako==1.3.0
+mako==1.3.3
     # via alembic
-markupsafe==2.1.3
+markupsafe==2.1.5
     # via
     #   jinja2
     #   mako
     #   werkzeug
-marshmallow==3.20.1
+marshmallow==3.21.2
     # via
     #   -r requirements.in
     #   flask-marshmallow
@@ -85,25 +83,23 @@ marshmallow==3.20.1
     #   webargs
 marshmallow-enum==1.5.1
     # via -r requirements.in
-marshmallow-sqlalchemy==0.29.0
+marshmallow-sqlalchemy==1.0.0
     # via -r requirements.in
-packaging==23.2
+packaging==24.0
     # via
-    #   flask-marshmallow
     #   marshmallow
-    #   marshmallow-sqlalchemy
     #   webargs
 psycopg2==2.9.9
     # via -r requirements.in
-pycparser==2.21
+pycparser==2.22
     # via cffi
-python-dateutil==2.8.2
+python-dateutil==2.9.0.post0
     # via
     #   faker
     #   icalendar
-python-dotenv==1.0.0
+python-dotenv==1.0.1
     # via -r requirements.in
-pytz==2023.3.post1
+pytz==2024.1
     # via
     #   -r requirements.in
     #   icalendar
@@ -113,25 +109,23 @@ requests==2.31.0
     #   flask-multipass
 six==1.16.0
     # via python-dateutil
-sqlalchemy==2.0.23
+sqlalchemy==2.0.30
     # via
     #   -r requirements.in
     #   alembic
     #   flask-sqlalchemy
     #   marshmallow-sqlalchemy
-typing-extensions==4.8.0
+typing-extensions==4.11.0
     # via
     #   alembic
     #   sqlalchemy
-urllib3==2.1.0
+urllib3==2.2.1
     # via requests
-webargs==8.3.0
+webargs==8.4.0
     # via -r requirements.in
-werkzeug==3.0.1
+werkzeug==3.0.3
     # via
     #   -r requirements.in
     #   flask
-xlsxwriter==3.1.9
+xlsxwriter==3.2.0
     # via -r requirements.in
-zipp==3.17.0
-    # via importlib-metadata
diff --git a/ruff.toml b/ruff.toml
new file mode 100644
index 000000000..a66f69c04
--- /dev/null
+++ b/ruff.toml
@@ -0,0 +1,149 @@
+target-version = 'py312'
+
+[lint]
+preview = true
+
+select = [
+    'E',      # pycodestyle
+    'F',      # pyflakes
+    'N',      # pep8-naming
+    'Q',      # flake8-quotes
+    'RUF',    # ruff
+    'UP',     # pyupgrade
+    'D',      # pydocstyle
+    'S',      # flake8-bandit
+    'C4',     # flake8-comprehensions
+    'INT',    # flake8-gettext
+    'LOG',    # flake8-logging
+    'B',      # flake8-bugbear
+    'A001',   # flake8-builtins
+    'COM',    # flake8-commas
+    'T10',    # flake8-debugger
+    'EXE',    # flake8-executable
+    'ISC',    # flake8-implicit-str-concat
+    'PIE',    # flake8-pie
+    'PT',     # flake8-pytest-style
+    'RSE',    # flake8-raise
+    'RET504', # flake8-return
+    'SIM',    # flake8-simplify
+    'TID',    # flake8-tidy-imports
+    'PGH',    # pygrep-hooks
+    'PL',     # pylint
+    'TRY',    # tryceratops
+    'PERF',   # perflint
+    'FURB',   # refurb
+    'I',      # isort
+]
+ignore = [
+    'E226',    # allow omitting whitespace around arithmetic operators
+    'E731',    # allow assigning lambdas (it's useful for single-line functions defined inside other functions)
+    'N818',    # not all our exceptions are errors
+    'RUF012',  # ultra-noisy and dicts in classvars are very common
+    'RUF015',  # not always more readable, and we don't do it for huge lists
+    'RUF022',  # autofix messes up our formatting instead of just sorting
+    'RUF027',  # also triggers on i18n functions -> too noisy for now
+    'UP038',   # it looks kind of weird and it slower than a tuple
+    'D205',    # too many docstrings which have no summary line
+    'D301',    # https://github.com/astral-sh/ruff/issues/8696
+    'D1',      # we have way too many missing docstrings :(
+    'D412',    # we do not use section, and in click docstrings those blank lines are useful
+    'S101',    # we use asserts outside tests, and do not run python with `-O` (also see B011)
+    'S113',    # enforcing timeouts would likely require config in some places - maybe later
+    'S311',    # false positives, it does not care about the context
+    'S324',    # all our md5/sha1 usages are for non-security purposes
+    'S404',    # useless, triggers on *all* subprocess imports
+    'S403',    # there's already a warning on using pickle, no need to have one for the import
+    'S405',    # we don't use lxml in unsafe ways
+    'S603',    # useless, triggers on *all* subprocess calls: https://github.com/astral-sh/ruff/issues/4045
+    'S607',    # we trust the PATH to be sane
+    'B011',    # we don't run python with `-O` (also see S101)
+    'B904',    # possibly useful but too noisy
+    'PIE807',  # `lambda: []` is much clearer for `load_default` in schemas
+    'PT004',   # pretty weird + not a pytest convention: https://github.com/astral-sh/ruff/issues/8796
+    'PT005',   # ^ likewise
+    'PT011',   # very noisy
+    'PT015',   # nice for tests but not so nice elsewhere
+    'PT018',   # ^ likewise
+    'SIM102',  # sometimes nested ifs are more readable
+    'SIM103',  # sometimes this is more readable (especially when checking multiple conditions)
+    'SIM105',  # try-except-pass is faster and people are used to it
+    'SIM108',  # noisy ternary
+    'SIM114',  # sometimes separate ifs are more readable (especially if they just return a bool)
+    'SIM117',  # nested context managers may be more readable
+    'PLC0415', # local imports are there for a reason
+    'PLC2701', # some private imports are needed
+    'PLR09',   # too-many-<whatever> is just noisy
+    'PLR0913', # very noisy
+    'PLR2004', # extremely noisy and generally annoying
+    'PLR6201', # sets are faster (by a factor of 10!) but it's noisy and we're in nanoseconds territory
+    'PLR6301', # extremely noisy and generally annoying
+    'PLW0108', # a lambda often makes it more clear what you actually want
+    'PLW1510', # we often do not care about the status code of commands
+    'PLW1514', # we expect UTF8 environments everywhere
+    'PLW1641', # false positives with SA comparator classes
+    'PLW2901', # noisy and reassigning to the loop var is usually intentional
+    'TRY002',  # super noisy, and those exceptions are pretty exceptional anyway
+    'TRY003',  # super noisy and also useless w/ werkzeugs http exceptions
+    'TRY300',  # kind of strange in many cases
+    'TRY301',  # sometimes doing that is actually useful
+    'TRY400',  # not all exceptions need exception logging
+    'PERF203', # noisy, false positives, and not applicable for 3.11+
+    'FURB113', # less readable
+    'FURB140', # less readable and actually slower in 3.12+
+    'PLW0603', # globals are fine here
+    'COM812',  # formatter conflict
+    'ISC001',  # formatter conflict
+]
+
+extend-safe-fixes = [
+    'RUF005',  # we typically don't deal with objects overriding `__add__` ir `__radd__`
+    'C4',      # they seem pretty safe
+    'UP008',   # ^ likewise
+    'D200',    # ^ likewise
+    'D400',    # ^ likewise
+    'PT014',   # duplicate test case parametrizations are never intentional
+    'RSE102',  # we do not use `raise func()` (with `func` returning the exception instance)
+    'RET504',  # looks pretty safe
+    'SIM110',  # ^ likewise
+    'PERF102', # ^ likewise
+]
+
+[format]
+quote-style = 'single'
+exclude = ['newdle/vendor/*.py']
+
+[lint.flake8-builtins]
+builtins-ignorelist = ['id', 'format', 'input', 'type', 'credits']
+
+[lint.flake8-pytest-style]
+fixture-parentheses = false
+mark-parentheses = false
+parametrize-names-type = 'tuple'
+parametrize-values-type = 'tuple'
+parametrize-values-row-type = 'tuple'
+
+[lint.flake8-tidy-imports]
+ban-relative-imports = 'all'
+
+[lint.flake8-quotes]
+inline-quotes = 'single'
+multiline-quotes = 'double'
+docstring-quotes = 'double'
+avoid-escape = true
+
+[lint.pep8-naming]
+classmethod-decorators = [
+    'classmethod',
+    'declared_attr',
+    'expression',
+    'comparator',
+]
+
+[lint.pydocstyle]
+convention = 'pep257'
+
+[lint.per-file-ignores]
+# vendored code - don't care about most stuff in there
+'newdle/vendor/*.py' = ['N', 'F841', 'UP', 'D', 'PIE', 'TID252', 'TRY']
+# allow long lines in migrations (only do that for raw SQL please)
+'newdle/migrations/versions/*.py' = ['E501', 'D400']
diff --git a/setup.cfg b/setup.cfg
index 09c5dd080..42d1d55ac 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -13,17 +13,4 @@ url = https://github.com/indico/newdle
 packages = find:
 zip_safe = false
 include_package_data = true
-python_requires = ~=3.9
-
-
-[flake8]
-exclude=newdle/client,__pycache__
-max-line-length=89
-
-inline-quotes = single
-multiline-quotes = single
-docstring-quotes = double
-avoid-escape = true
-
-per-file-ignores =
-    newdle/vendor/django_mail/**/*.py:Q
+python_requires = ~=3.12
diff --git a/tests/models_test.py b/tests/models_test.py
index 8204e94e5..d84c47308 100644
--- a/tests/models_test.py
+++ b/tests/models_test.py
@@ -83,7 +83,7 @@ def test_code_generation(db_session, monkeypatch):
 
     # simulate a situation in which there is a collision with the code
     # of an existing newdle
-    class _MockRandom(object):
+    class _MockRandom:
         def __init__(self):
             self.collision = True