Microservices promise agility but often deliver distributed monoliths. Here's the architectural discipline that keeps services truly independent.

The Microservices Trap


We've audited dozens of microservice architectures and the pattern is consistent: teams start with the best intentions and end up with a distributed monolith that's slower to deploy, harder to debug, and more expensive to run than the monolith they left.


The Rules We Never Break


1. Services own their data

No shared databases. Ever. If two services need the same data, one of them is wrong about its service boundaries.


2. Async by default

Synchronous service-to-service calls create coupling. Use events (Kafka, SNS) for anything that doesn't require an immediate response.


3. Define your API contract first

Write your OpenAPI spec before you write code. Services should be able to evolve independently behind stable interfaces.


4. Design for failure

Every downstream call can fail. Circuit breakers, retries with exponential backoff, and graceful degradation are non-negotiable.


When Not to Use Microservices


Startups and small teams: don't. A well-structured monolith is almost always the right starting point. Extract services when team ownership boundaries demand it, not before.