/microservices-patterns

name: microservices-patterns
type: reference
description: "Provides microservices design patterns for service decomposition, API gateway, circuit breakers, saga orchestration, and inter-service communication. Use when designing or implementing microservices architecture."
paths: ["**/docker-compose*", "**/k8s/**", "**/services/**"]
effort: 4
allowed-tools: Read, Glob, Grep, Write, Edit, Bash
user-invocable: true
when_to_use: "When designing microservices architecture, implementing service communication, or decomposing monoliths"

Microservices Patterns

Service decomposition, communication, resilience, and orchestration patterns.

Service Decomposition

| Pattern | Description | Use When | |---------|-------------|----------| | Domain-Driven | Align services with bounded contexts | Complex business domains | | Data-Ownership | Service owns its data store | Data isolation required | | Team-Aligned | One service per team | Large organizations |

Communication Patterns

Sync: HTTP/gRPC

\`\`\`yaml

API Gateway routing

routes:

• match: { prefix: /orders }

route: { cluster: order-service }

• match: { prefix: /users }

route: { cluster: user-service } \`\`\`

Async: Message Queue

\`\`\` Producer → Exchange → Queue → Consumer (Topic) (DLQ on failure) \`\`\`

Use async for: event propagation, eventual consistency, load leveling.

Resilience Patterns

Circuit Breaker

\`\`\`typescript // Example with opossum const breaker = new CircuitBreaker(fetchUserProfile, { timeout: 3000, errorThresholdPercentage: 50, resetTimeout: 30000, }); \`\`\`

Retry with Backoff

\`\`\`typescript async function retryWithBackoff(fn, maxRetries = 3) { for (let i = 0; i < maxRetries; i++) { try { return await fn(); } catch (e) { await sleep(Math.pow(2, i) * 1000); } } throw new Error('Max retries exceeded'); } \`\`\`

Data Patterns

| Pattern | Consistency | Complexity | Use When | |---------|-------------|------------|----------| | Saga (orchestration) | Eventual | High | Complex multi-service transactions | | Saga (choreography) | Eventual | Medium | Simple event chains | | Event sourcing | Eventual | High | Audit trail, time travel | | Shared database | Strong | Low | Anti-pattern, avoid |

API Gateway

Tools: Kong, AWS API Gateway, Envoy, NGINX.

Responsibilities: routing, auth, rate limiting, request transformation, load balancing.

Observability Stack

• Distributed tracing: Jaeger / Tempo
• Metrics: Prometheus + Grafana
• Logs: ELK / Loki
• Service mesh: Istio / Linkerd (adds mTLS, traffic management)

Related Skills

• `backend-architect` — single-service architecture
• `event-sourcing-architect` — event sourcing patterns
• `kubernetes-architect` — deployment patterns
• `deployment-engineer` — CI/CD for microservices