Cinema Microservice

Overview

Cinema Microservice was built during a two-week internship training program. The task was to learn .NET and build a microservice-based backend for a cinema domain. The system includes 7 services: IdentityService (JWT/OAuth), StudioService, MovieService, ScheduleService, TicketService, TransactionService, and Ocelot API Gateway. This was my first exposure to C# and the .NET ecosystem.

Problem

The internship training required learning .NET and building a microservice within two weeks
I needed to understand C#, Entity Framework Core, and the .NET dependency injection system from scratch
The cinema domain required handling shows, seats, bookings, and payments across multiple services

Goal

Learn .NET fundamentals and build working microservices
Implement service separation with NATS message broker for inter-service communication
Add Redis caching, Ocelot API Gateway, and Kubernetes deployment manifests

Role

I built the backend services independently during the training period.

Team: Achmad Raihan Fahrezi Effendy (Backend Developer)

Architecture

flowchart TD A["Ocelot API Gateway"] --> B["IdentityService"] A --> C["MovieService"] A --> D["ScheduleService"] A --> E["TicketService"] A --> F["TransactionService"] A --> G["StudioService"] B --> H[("MSSQL")] C --> H D --> H E --> H F --> H G --> H B --> I["Redis Cache"] C --> I E --> I J["NATS Message Broker"] --> B J --> C J --> E J --> F K["Kubernetes"] --> A K --> B K --> C

Layer	Technology	Purpose
Framework	.NET Core 8 (C#)	Backend services
ORM	Entity Framework Core	Code-first database access
Database	Microsoft SQL Server	Persistent storage
Cache	Redis	Caching and session management
Messaging	NATS	Inter-service communication
Gateway	Ocelot	API routing and aggregation
Container	Docker, Kubernetes	Deployment and orchestration

Key Features

7 Microservices — Identity, Movie, Studio, Schedule, Ticket, Transaction, API Gateway
JWT/OAuth Authentication — IdentityService handles auth across all services
NATS Messaging — Asynchronous communication between services
Redis Caching — Cached frequently accessed data (movies, schedules)
Ocelot Gateway — Unified entry point with routing and rate limiting
Kubernetes Manifests — Deployment configs for container orchestration

Technical Decisions

.NET was required by the training program
Entity Framework Core was used because it is the standard ORM in the .NET ecosystem
NATS was chosen for lightweight inter-service messaging
Ocelot provided a simple API gateway without the overhead of Kong or Envoy
Kubernetes manifests were included to demonstrate container orchestration knowledge

Challenges

Learning C# and .NET in two weeks while building a working project was intense
The dependency injection system in .NET is more explicit than in NestJS — understanding service lifetimes took time
Debugging across 7 services required learning new tools and distributed tracing concepts

Outcome

The project was completed during the training period and demonstrated working microservice communication with NATS, Redis caching, and Ocelot routing. It showed me that backend concepts transfer across languages.

Final Thoughts

Cinema Microservice taught me that the language matters less than the patterns. Dependency injection, service separation, and message brokers work the same way whether you use TypeScript, PHP, or C#. The two weeks were intense, but the breadth of experience was worth it.