Microservices in Go: lessons from production

Microservices are not a goal but a tool

Splitting a system into services for the sake of fashion is a sure path to a distributed monolith that is harder than the original. Microservices are justified when you need to scale parts of the system independently and give teams autonomy.

Where to draw the boundaries

We draw service boundaries by domains, relying on the bounded contexts from DDD. Each service owns its data — a shared database between services is an anti-pattern that leads to hidden coupling.

Principles that proved themselves

• A separate storage for each service.
• Asynchronous event exchange instead of chains of synchronous calls.
• Explicit, versioned contracts between services.

Data consistency

In a distributed system there are no global transactions. We use the saga pattern for long-running business operations and the transactional outbox for reliable event publishing without loss or duplication.

Fault tolerance and observability

Timeouts, retries with backoff, a circuit breaker and idempotent handlers protect against cascading failures. Correlation IDs, metrics and distributed tracing make a request path through dozens of services visible.

Conclusion

Microservices give enormous flexibility but require a mature engineering culture. Start with a well-structured monolith and extract services when there are real reasons to do so.