diff --git a/Dockerfile b/Dockerfile
index 063122a84..e3e9f7a72 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,10 +3,6 @@ FROM ruby:2.4
 # Cleanup expired Let's Encrypt CA (Sept 30, 2021)
 RUN sed -i '/^mozilla\/DST_Root_CA_X3/s/^/!/' /etc/ca-certificates.conf && update-ca-certificates -f
 
-RUN apt-get update && \
-    apt-get install -y cron && \
-    apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
 # Create a user for the web app.
 RUN addgroup --gid 9999 app && \
     adduser --uid 9999 --gid 9999 --disabled-password --gecos "Application" app && \
@@ -19,9 +15,11 @@ WORKDIR /app
 # Configuration
 ARG gemfile=Gemfile
 ENV BUNDLE_GEMFILE=${gemfile}
-ENV PUMA_OPTIONS "--preload -w 4 -p 3000"
-ENV NNDD_VERSION "cdx-0.11-pre7"
+ENV PUMA_OPTIONS="--preload -w 4 -p 3000"
+ENV NNDD_VERSION="cdx-0.11-pre7"
 ENV RAILS_ENV=production
+ENV RAILS_LOG_TO_STDOUT=true
+ENV RAILS_SERVE_STATIC_FILES=true
 
 # Install gem bundle
 COPY Gemfile* cdx.gemspec cdx-api-elasticsearch.gemspec /app/
@@ -45,4 +43,4 @@ RUN /app/docker/config-nndd
 RUN mkdir -p /app/tmp /app/log && chown -R app:app /app/tmp /app/log
 
 EXPOSE 3000
-CMD ["/app/docker/web-run"]
+CMD bundle exec puma $PUMA_OPTIONS -e $RAILS_ENV
diff --git a/Gemfile b/Gemfile
index 5ff64d8f5..714c78973 100644
--- a/Gemfile
+++ b/Gemfile
@@ -74,8 +74,7 @@ gem 'geojson_import', git: 'https://github.com/instedd/geojson_import', branch:
 # Services
 gem 'puma', '~> 3.0'
 gem 'sidekiq', '~> 4.2'
-gem 'sidekiq-cron', '~> 0.3' # TODO: not maintained, consider sidekiq-scheduler instead
-gem 'whenever', '~> 1.0' # TODO: replace with a sidekiq-cron job
+gem 'sidekiq-cron'
 
 # External services
 gem 'location_service', git: 'https://github.com/instedd/ruby-location_service.git', branch: 'master'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7a0b7b4f6..01e1a542a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -124,7 +124,6 @@ GEM
       capybara (>= 1.0, < 4)
       launchy
     childprocess (3.0.0)
-    chronic (0.10.2)
     chunky_png (1.4.0)
     climate_control (0.2.0)
     cocaine (0.5.8)
@@ -137,7 +136,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.2.0)
     config (1.7.2)
       activesupport (>= 3.0)
       deep_merge (~> 1.2, >= 1.2.1)
@@ -250,7 +249,7 @@ GEM
     ffi (1.15.5)
     filewatcher (0.3.6)
       trollop (~> 2.0)
-    fugit (1.8.0)
+    fugit (1.8.1)
       et-orbi (~> 1, >= 1.2.7)
       raabro (~> 1.4)
     gherkin (5.1.0)
@@ -482,8 +481,6 @@ GEM
     ruby_parser (3.19.2)
       sexp_processor (~> 4.16)
     rubyzip (2.3.2)
-    rufus-scheduler (3.8.2)
-      fugit (~> 1.1, >= 1.1.6)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
@@ -506,8 +503,8 @@ GEM
       connection_pool (~> 2.2, >= 2.2.0)
       rack-protection (>= 1.5.0)
       redis (~> 3.2, >= 3.2.1)
-    sidekiq-cron (0.6.3)
-      rufus-scheduler (>= 3.3.0)
+    sidekiq-cron (1.2.0)
+      fugit (~> 1.1)
       sidekiq (>= 4.2.1)
     simplecov (0.18.5)
       docile (~> 1.1)
@@ -541,7 +538,7 @@ GEM
     ttfunk (1.6.2.1)
     turbolinks (2.5.4)
       coffee-rails
-    tzinfo (1.2.10)
+    tzinfo (1.2.11)
       thread_safe (~> 0.1)
     uglifier (2.7.2)
       execjs (>= 0.3.0)
@@ -563,8 +560,6 @@ GEM
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
-    whenever (1.0.0)
-      chronic (>= 0.6.3)
     xpath (3.2.0)
       nokogiri (~> 1.8)
 
@@ -645,7 +640,7 @@ DEPENDENCIES
   selenium-webdriver (< 4.0)
   sentry-raven (~> 2.13)
   sidekiq (~> 4.2)
-  sidekiq-cron (~> 0.3)
+  sidekiq-cron
   simplecov
   site_prism (~> 3.0)
   spring
@@ -659,7 +654,6 @@ DEPENDENCIES
   view_components!
   web-console (< 4.0)
   webmock (~> 2.3.1)
-  whenever (~> 1.0)
 
 BUNDLED WITH
    1.17.3
diff --git a/app/jobs/cleanup_assay_files_job.rb b/app/jobs/cleanup_assay_files_job.rb
new file mode 100644
index 000000000..92c063c70
--- /dev/null
+++ b/app/jobs/cleanup_assay_files_job.rb
@@ -0,0 +1,10 @@
+class CleanupAssayFilesJob
+  include Sidekiq::Worker
+
+  # Delete AssayFile that don't have any AssayAttachment (parent model) associated.
+  def perform
+    AssayFile
+      .where("created_at > ? AND assay_attachment_id IS NULL", 7.days.ago)
+      .find_each(&:destroy)
+  end
+end
diff --git a/app/jobs/daily_alert_job.rb b/app/jobs/daily_alert_job.rb
index dc3e52901..94cbb3ecd 100644
--- a/app/jobs/daily_alert_job.rb
+++ b/app/jobs/daily_alert_job.rb
@@ -8,8 +8,3 @@ def perform
     alert_history_check(1.day, Alert.aggregation_frequencies["day"])
   end
 end
-
-# note: an alternative gem for scheduling cron jobs could be:  http://github.com/javan/whenever but
-# the advantage of gem "sidekiq-cron" is that it appears in the sidekiq web url , http://localhost:3000/sidekiq/cron
-
-Sidekiq::Cron::Job.create(name: 'Alert Daily - daily 12:15am', cron: '15 0 * * *', klass: 'DailyAlertJob')   #run daily at 15 after midnight
diff --git a/app/jobs/daily_demo_data.rb b/app/jobs/daily_demo_data.rb
index 031cec6b9..1d9eafb5e 100644
--- a/app/jobs/daily_demo_data.rb
+++ b/app/jobs/daily_demo_data.rb
@@ -3,23 +3,22 @@
 class DailyDemoData
   include Sidekiq::Worker
 
-  #just paste here, we can move this value into an env setting once we start to use this tool 
+  #just paste here, we can move this value into an env setting once we start to use this tool
   def get_repeat_demo_per_device
     1000
   end
-  
+
   ##
   # Note: it is assumed that rake db:ssed has been called to load the seeds data generated.
   #
   # if say 1000 daily testresults are needed per device, then loop over the device templates (only two templates at the moment)
-  def perform   
-    insert_demo_data(get_repeat_demo_per_device) 
+  def perform
+    insert_demo_data(get_repeat_demo_per_device)
   end
- 
+
 end
 
-# note: an alternative gem for scheduling cron jobs could be:  http://github.com/javan/whenever but
-# the advantage of gem "sidekiq-cron" is that it appears in the sidekiq web url , http://localhost:3000/sidekiq/cron
 if use_demo_data?
-  Sidekiq::Cron::Job.create(name: 'Demo Data - daily 12:15am', cron: '15 0 * * *', klass: 'DailyDemoData')   #run daily at 15 after midnight
+  # run daily at 15 after midnight
+  Sidekiq::Cron::Job.create(name: 'Demo Data - daily 12:15am', cron: '15 0 * * *', klass: 'DailyDemoData')
 end
diff --git a/app/jobs/hourly_alert_job.rb b/app/jobs/hourly_alert_job.rb
index 018b4f83e..f138bcb44 100644
--- a/app/jobs/hourly_alert_job.rb
+++ b/app/jobs/hourly_alert_job.rb
@@ -8,11 +8,3 @@ def perform
     alert_history_check(1.hour, Alert.aggregation_frequencies["hour"])
   end
 end
-
-# note: an alternative gem for scheduling cron jobs could be:  http://github.com/javan/whenever but
-# the advantage of gem "sidekiq-cron" is that it appears in the sidekiq web url , http://localhost:3000/sidekiq/cron
-
-Sidekiq::Cron::Job.create(name: 'Alert Hourly - hourly', cron: '0 * * * *', klass: 'HourlyAlertJob')   #run each hour
-
-#for test run every 5 mins:
-#Sidekiq::Cron::Job.create(name: 'Alert Hourly - 10mins 12:15am', cron: '*/10 * * * *', klass: 'HourlyAlertJob')   #run daily at 15 after midnight
diff --git a/app/jobs/hourly_utilization_efficiency_job.rb b/app/jobs/hourly_utilization_efficiency_job.rb
index c8522b465..4317b9dcc 100644
--- a/app/jobs/hourly_utilization_efficiency_job.rb
+++ b/app/jobs/hourly_utilization_efficiency_job.rb
@@ -20,11 +20,11 @@ def perform
         #convert the aggregation [days or hours] into hours for calculations
         hours_per_day = 24
         if alert.aggregation_frequency == "month"
-          utilization_efficiency_hours = amount * hours_per_day * 30 
+          utilization_efficiency_hours = amount * hours_per_day * 30
         elsif alert.aggregation_frequency == "week"
-          utilization_efficiency_hours = amount * hours_per_day * 7 
+          utilization_efficiency_hours = amount * hours_per_day * 7
         elsif alert.aggregation_frequency == "day"
-          utilization_efficiency_hours = amount * hours_per_day 
+          utilization_efficiency_hours = amount * hours_per_day
         else
           utilization_efficiency_hours = amount
         end
@@ -51,10 +51,3 @@ def perform
     end
   end
 end
-
-#run every 30 mins to give more accuracy, +/- 30 mins
-Sidekiq::Cron::Job.create(name: 'Alert Utilization Efficiency - hourly', cron: '*/30 * * * *', klass: 'HourlyUtilizationEfficiencyJob')
-
-
-#every 2 minsutes for testing
-#Sidekiq::Cron::Job.create(name: 'Alert Utilization Efficiency - hourly', cron: '*/2 * * * *', klass: 'HourlyUtilizationEfficiencyJob')
diff --git a/app/jobs/monthly_alert_job.rb b/app/jobs/monthly_alert_job.rb
index 6db630b72..cddb55b13 100644
--- a/app/jobs/monthly_alert_job.rb
+++ b/app/jobs/monthly_alert_job.rb
@@ -8,7 +8,3 @@ def perform
     alert_history_check(1.month, Alert.aggregation_frequencies["month"])
   end
 end
-
-Sidekiq::Cron::Job.create(name: 'Alert Monthly - daily 12:15am', cron: '35 0 * * *', klass: 'MonthlyAlertJob')   #run daily at 35 after midnight
-
-#Sidekiq::Cron::Job.create(name: 'Alert Monthly - 10mins 12:15am', cron: '*/5 * * * *', klass: 'MonthlyAlertJob') 
diff --git a/app/jobs/weekly_alert_job.rb b/app/jobs/weekly_alert_job.rb
index a5de7007a..690792f91 100644
--- a/app/jobs/weekly_alert_job.rb
+++ b/app/jobs/weekly_alert_job.rb
@@ -8,6 +8,3 @@ def perform
     alert_history_check(1.week, Alert.aggregation_frequencies["week"])
   end
 end
-
-Sidekiq::Cron::Job.create(name: 'Alert Weekly - daily 12:15am', cron: '25 0 * * *', klass: 'WeekyAlertJob')   #run daily at 25 after midnight
-
diff --git a/config/initializers/sidekiq.rb b/config/initializers/sidekiq.rb
new file mode 100644
index 000000000..34033456b
--- /dev/null
+++ b/config/initializers/sidekiq.rb
@@ -0,0 +1,26 @@
+Sidekiq.configure_server do |config|
+  config.on(:startup) do
+    # run daily at 15 after midnight
+    Sidekiq::Cron::Job.create(name: 'Alert Daily - daily 12:15am', cron: '15 0 * * *', klass: 'DailyAlertJob')
+
+    # run daily at 25 after midnight
+    Sidekiq::Cron::Job.create(name: 'Alert Weekly - daily 12:15am', cron: '25 0 * * *', klass: 'WeekyAlertJob')
+
+    # run daily at 35 after midnight
+    Sidekiq::Cron::Job.create(name: 'Alert Monthly - daily 12:15am', cron: '35 0 * * *', klass: 'MonthlyAlertJob')
+
+    # run hourly
+    Sidekiq::Cron::Job.create(name: 'Alert Hourly - hourly', cron: '0 * * * *', klass: 'HourlyAlertJob')
+
+    # run every 30 mins to give more accuracy, +/- 30 mins
+    Sidekiq::Cron::Job.create(name: 'Alert Utilization Efficiency - hourly', cron: '*/30 * * * *', klass: 'HourlyUtilizationEfficiencyJob')
+
+    # for manual tests (run every some 2, 5 or 10 mins):
+    # Sidekiq::Cron::Job.create(name: 'Alert Utilization Efficiency - hourly', cron: '*/2 * * * *', klass: 'HourlyUtilizationEfficiencyJob')
+    # Sidekiq::Cron::Job.create(name: 'Alert Monthly - 10mins 12:15am', cron: '*/5 * * * *', klass: 'MonthlyAlertJob')
+    # Sidekiq::Cron::Job.create(name: 'Alert Hourly - 10mins 12:15am', cron: '*/10 * * * *', klass: 'HourlyAlertJob')
+
+    # run daily at 02:00am
+    Sidekiq::Cron::Job.create(name: 'Cleanup unused AssayFile', cron: '0 2 * * *', klass: 'CleanupAssayFilesJob')
+  end
+end
diff --git a/config/schedule.rb b/config/schedule.rb
deleted file mode 100644
index 51cdef76a..000000000
--- a/config/schedule.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-# Use this file to easily define all of your cron jobs.
-#
-#
-require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
-
-set :output, "./cron_log.log"
-set :environment, Rails.env
-
-# GEM_PATH and other environment variables are not being correctly loaded when running in a crontab
-# so we load them in the job to be able to run it
-# see: https://github.com/javan/whenever/issues/656
-ENV.each { |k, v| env(k, v) }
-
-every 1.week do
-  rake "assay_files:garbage_collector"
-end
diff --git a/docker/web-run b/docker/web-run
deleted file mode 100755
index ad9635a98..000000000
--- a/docker/web-run
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/bash
-source /etc/envvars
-cd /app
-exec su -p -c "bundle exec whenever --update-crontab && bundle exec puma $PUMA_OPTIONS -e $RAILS_ENV" app
diff --git a/lib/tasks/assay_files.rake b/lib/tasks/assay_files.rake
deleted file mode 100644
index ea27031c7..000000000
--- a/lib/tasks/assay_files.rake
+++ /dev/null
@@ -1,7 +0,0 @@
-namespace :assay_files do
-  desc "delete AssayFiles that don't have any AssayAttachment (parent model) associated"
-  task garbage_collector: :environment do
-    assay_files = AssayFile.where("created_at > ? AND assay_attachment_id IS NULL", 7.days.ago)
-    AssayFile.destroy(assay_files.map(&:id))
-  end
-end