Microservices Design Patterns: 20+ Patterns Every Architect Must Know (2025 Guide)

Q: What are the most important microservices design patterns?

The top patterns are: API Gateway, Service Discovery, Circuit Breaker, Saga (for distributed transactions), CQRS, Event Sourcing, Strangler Fig (for migration), Sidecar, and Bulkhead. Start with API Gateway and Circuit Breaker as foundational patterns.

Q: When should you use microservices vs monolith?

Start with a monolith (or modular monolith) until you have clear scaling/deployment bottlenecks. Microservices add operational complexity — they are justified when you need independent scaling, polyglot tech stacks, or autonomous team deployments.

Q: What is the Saga pattern?

The Saga pattern manages distributed transactions across microservices as a sequence of local transactions. If one step fails, compensating transactions undo previous steps. Two types: choreography (event-driven) and orchestration (central coordinator).

Q: How do microservices communicate?

Synchronous: REST APIs, gRPC (for internal services). Asynchronous: message queues (SQS, RabbitMQ), event streams (Kafka, EventBridge). Best practice: synchronous for queries, asynchronous for commands and events.

Q: What is the strangler fig pattern?

The strangler fig pattern migrates from monolith to microservices incrementally. Route traffic through a facade, extract one feature at a time into a microservice, and gradually reroute until the monolith is fully replaced — no big-bang migration needed.