EventFlow Microservices

Overview

A multi-service event platform covering authentication, event lifecycle, ticketing, and notifications.

Challenge

An event platform needs auth, event lifecycle, ticketing, and notifications to evolve independently without a single deployable unit coupling them. Each domain must own its data, and cross-domain work must not require a synchronous call graph through every service.

Responsibilities

• Built the API gateway and its routing to each domain service.
• Implemented JWT authentication with registration and login.
• Implemented the event, ticket, and notification services with their DTOs, schemas, and Kafka topics.
• Wired Docker Compose for the local multi-service stack.

Solution

Put each domain behind its own service with a single gateway in front, and move cross-domain work onto an event bus instead of direct service-to-service calls.

Architecture

NestJS services (API gateway, auth, events, tickets, notifications) communicating over Kafka (kafkajs), PostgreSQL accessed through Drizzle ORM, JWT and bcrypt for authentication, Jest/Supertest for tests, Docker for local orchestration.

Technical decisions and trade-offs

• Chose Kafka as the transport for cross-service events so a service can be redeployed without the others being online, at the cost of eventual consistency and more moving parts locally.
• Kept a single API gateway as the only public entry point so clients never address individual services, which adds a hop but centralizes auth and routing.
• Used Drizzle ORM instead of TypeORM for typed SQL close to the schema, trading the richer decorator-based abstraction for explicit queries.
• Split the work service-by-service across commits so each boundary could be reviewed on its own.

Outcomes

• The repository runs as a documented local multi-service stack via Docker Compose with docker-compose.yml and Dockerfile present.
• Jest + Supertest test harness and end-to-end test entry points are present for the gateway and services.

Lessons learned

• Build output (dist/) ended up committed alongside sources; separating generated files from the reviewable diff would have made the service boundaries easier to read.

Technologies

• NestJS
• Kafka
• PostgreSQL
• Drizzle ORM
• Docker
• Jest
• Supertest