Avoiding Common Pitfalls in Microservice Architectures
A common mistake I see in microservice architectures is the use of Remote Procedure Calls (RPC) or even REST-based synchronous communication between services. While this may seem like a straightforward way for services to interact, it fundamentally breaks the promise of what microservices should deliver—both from a technical and socio-technical perspective.
Instead of thinking about services as functions that are remotely called, we should adopt the mindset of Autonomous Components. This is a concept championed by Udi Dahan long before “microservices” became a buzzword. Here’s why making this paradigm shift is crucial:
1. Temporal Coupling Link to heading
RPC requires both services to be online at the same time. This fragile dependency drastically reduces the fault tolerance of your system—if service B is down, service A fails. True microservices should be autonomous, able to handle requests without needing other services to be available in real-time.
2. Autonomy Over Remote Calls Link to heading
Microservices should be treated as Autonomous Components, capable of fulfilling an entire request independently. This means a service must handle its business logic without having to call another remote service to fetch data or perform actions. Any data required from other services should be pre-loaded via events or asynchronous messages, rather than fetched on demand through synchronous RPC.
3. Service Contracts and Team Isolation Link to heading
One of the key reasons for adopting microservices is the socio-technical advantage: enabling teams to work in isolation and deploy independently. Service contracts help facilitate this by defining clear boundaries. However, if services rely on RPC or REST-based calls, service A cannot fully implement or test new features until service B is deployed and available. This creates deployment bottlenecks and undermines team autonomy—which is the entire point of using microservices.
4. Message Brokers Aren’t a Fix Link to heading
Adding a message broker between services isn’t enough to solve these problems. If the core issue of tight coupling remains, you’re simply turning synchronous problems into asynchronous ones, often adding complexity without real benefits. The key is to design services that are autonomous by design, not just by communication style.
Building Decoupled Systems Link to heading
To build truly decoupled systems, adopt event-driven architectures where services communicate asynchronously and handle their own data. Services should publish events when data changes, and other services can react to those events as needed. This avoids direct dependencies and allows teams to work, test, and deploy independently, unlocking the true power of microservices.
The ultimate goal of microservices is loose coupling, high autonomy, and team independence. Moving away from RPC towards an autonomous component model ensures that both your systems and your teams can scale effectively.