CryptoTracker

To start your Phoenix server:

• Run mix setup to install and setup dependencies
• Start Phoenix endpoint with mix phx.server or inside IEx with iex -S mix phx.server

Now you can visit localhost:4000 from your browser.

Ready to run in production? Please check our deployment guides.

CryptoTracker Improvements Checklist

✅ Completed

• Implemented a mocked price fetcher for development
• Created CryptoTracker.Fetcher to fetch live prices from CoinMarketCap API
• Added environment variable support for API key via .env files
• Implemented a PriceTracker GenServer per coin
• Introduced CoinTrackerSupervisor (DynamicSupervisor) to manage coin processes
• Set up Registry to uniquely identify each coin GenServer
• Price fetching and database insertion works correctly
• Handled :utc_datetime microseconds issue with DB inserts

☐ To Improve

• Switch from Process.send_after to :timer.send_interval for fixed update intervals
• Add retry/backoff logic for API failures to prevent temporary outages from crashing the GenServer
• Decouple fetching from database writes for better fault tolerance
• Introduce telemetry events to track fetch success, latency, and errors
• Configure an in-memory cache (ETS or :persistent_term) for fast price reads
• Enable dynamic addition of new coins at runtime
• Implement global rate limiting to respect CoinMarketCap API quotas
• Create a mock/stub Fetcher for tests to avoid hitting the real API
• Add logging/alerts for repeated GenServer crashes or failed fetches