Crypto Investment

Crypto Investment is a cryptocurrency recommendation service for developers. The service helps developers choose which cryptocurrency to invest in. Since the developers may not have much knowledge about cryptocurrencies, the service will act as a guide and make recommendations on which cryptocurrencies to choose.

Running the service locally

git clone [email protected]:artemalexpetrov/crypto-currencies.git
cd crypto-currencies
docker-compose -f docker-compose-prod.yaml --env-file docker.env up -d

Open http://127.0.0.1:8080/docs/ui to explore available REST API endpoints.

Configuration

There are some of available configuration properties are available in the docker.env file:

Property	Default Value	Description
IMPORTER_PORT	8085	Host port to map container that running the importer application
IMPORTER_MANAGEMENT_PORT	8086	Management port for the Importer application
IMPORT_DATA_HOST_DIRECTORY	.data	Directory that contains CSV files to import
API_PORT	8080	Host port to map container that running the API application
API_MANAGEMENT_PORT	8081	Management port for the API application
API_MAX_REQUESTS_PER_MINUTE	60	Requests rate limit
OPENAPI_URL	/docs/api	A URI to download docs in OpenAPI format
SWAGGER_URL	/docs/ui	A URI to browse Swagger docs

Components

To ensure responsibility segregation and scalability, the application was implemented as two separate modules: crypto.investments.api and crypto.investments.importer. Each of these modules is a standalone application.

Component	Description
crypto.investments.api	A SpringBoot application that provides access to imported currencies via REST API
crypto.investments.importer	A StringBoot application that imports currency values from CSV files. Utilized SpringBatch to support huge files and import recovery
Database	PostgreSQL Timescale. This DB was chosen to efficiently work with time-series
Redis	For caching and rate-limiting

Known issues & limitations

• The crypto.investments.importer moves imported files into <data>/.imported directory and remembers a name of imported file. Once a new file with same name is added into <data> directory importer ignores it. Temporary solution is to use timestamp in currency data filenames. Later it will be fixed with files checksums.

• The crypto.investments.api caches data fetched from a database. Cache eviction happens every N seconds. Actually the crypto.investments.importer should evict cache after import or send an event so other component can react on it and clear cache.

• Integration tests coverage should be improved