1. Setup and Configuration

   • Set up Node.js with Fastify for HTTP layer.
   • Set up PostgreSQL for relational database.
   • Set up Redis for ranking and caching.
   • Integrate Swagger/OpenAPI for API documentation.
   • Configure Sentry/Datadog for monitoring metrics.

2. Security and Performance

   • Implement JWT authentication for admin access.
   • Add rate limiting to prevent abuse.
   • Secure endpoints against SQL injection.
   • Ensure response times under 200ms

3. Core Features

   • Subscription: allow users to register in event with name and email.
   • Ensure users can only subscribe once and only during the event's start and end dates.
   • Generate unique referral links for subscribers.
   • Track direct and indirect referrals for each referral link.
   • Display the referral ranking ordered by the number of referrals.
   • Allow hosts to filter the referral links ranking by day.

4. Testing

   • Write tests with at least 90% coverage.
   • Set up continuous integration to run tests and check coverage.

5. Monitoring and Optimization

   • Track key metrics (requests per second, system load, response time).
   • Send performance data to Sentry/Datadog.
   • Optimize database and cache configurations regularly.

6. Documentation and Deployment

   • Document API endpoints using Swagger/OpenAPI.
   • Set up deployment using Docker.
   • Ensure proper security and performance settings in production.