I’ve been thinking a lot lately about how we build systems that are not just scalable, but also resilient and easy to maintain. In my work, I’ve seen firsthand how tangled microservices can become when communication is handled poorly. That’s why I decided to explore a more structured approach—one that combines the power of event-driven design with strong typing and modern tooling. If you’re looking to build distributed systems that are both robust and developer-friendly, you’re in the right place.

Let’s talk about building microservices with NestJS, RabbitMQ, and Prisma. This combination gives you a solid foundation for creating systems where services communicate through events, ensuring loose coupling and independent scalability. Have you ever wondered how to keep your services in sync without creating tight dependencies?

We start by setting up a workspace with multiple NestJS applications. Each service—whether it’s handling users, orders, or notifications—lives in its own package, sharing common types and configurations through a dedicated shared module. This structure promotes reusability and keeps your code organized.

Here’s a glimpse of how to initialize the project:

npx create-nx-workspace event-driven-microservices --preset=nest
cd event-driven-microservices
npm install @nestjs/microservices amqplib prisma

Next, we define our events. Type safety begins here, with well-structured event interfaces that every service can rely on. For instance, a user creation event might look like this:

export interface UserCreatedEvent {
  eventId: string;
  eventType: 'user.created';
  payload: {
    userId: string;
    email: string;
    firstName: string;
    lastName: string;
  };
}

With events defined, we move to infrastructure. Using Docker Compose, we spin up RabbitMQ and PostgreSQL instances for each service. This isolation ensures that services manage their own data without interference.

How do we handle message routing and ensure events reach the right services? RabbitMQ’s topic exchanges allow us to route messages based on patterns. Here’s a sample configuration for setting up an exchange:

export const rabbitMQConfig: RabbitMQConfig = {
  exchanges: [
    {
      name: 'events.exchange',
      type: 'topic',
      options: { durable: true },
    },
  ],
};

Each service connects to RabbitMQ and listens for events relevant to its domain. The user service, for example, might listen for user.* events, while the order service handles order.*. This pattern keeps concerns separated and makes it easy to extend the system later.

Prisma brings type-safe database operations to the mix. By generating a client tailored to your schema, you eliminate whole classes of errors related to data access. Here’s how you might define and use a Prisma client in the user service:

const prisma = new PrismaClient();

async function createUser(userData: CreateUserDto) {
  return prisma.user.create({
    data: userData,
  });
}

Error handling is critical in distributed systems. We implement retry mechanisms and dead-letter queues to manage failures gracefully. If a message can’t be processed, it moves to a DLX for later analysis without blocking the main flow.

Testing such a system requires a strategy that covers both individual services and their interactions. We use Dockerized test environments to simulate production conditions, ensuring our tests are both reliable and reproducible.

Deployment involves containerizing each service and orchestrating them with tools like Kubernetes. Monitoring becomes easier when each service reports its health and metrics independently.

Throughout this process, I’ve found that attention to detail pays off. Small decisions—like choosing consistent event naming or structuring shared code—have a big impact on maintainability.

What challenges have you faced when building microservices? How do you ensure your services remain decoupled yet coordinated?

I hope this walkthrough gives you a practical starting point for your own projects. If you found this useful, feel free to like, share, or comment with your thoughts and experiences. Let’s keep the conversation going.