Templates/Microservice Event-Driven

Microservice Event-Driven

MicroservicesAdvancedOrg critical

Domain-driven microservices with event sourcing, CQRS-style analytics write path, and dead-letter isolation. Use when services must evolve independently with async integration.

Recommended for: Event-driven microservices

11 nodes11 connectionsAsync processingAI-assisted flowsEvent backbone

Use Case

Event-driven microservices, domain-driven design, CQRS

Best Fit Scenarios

  • Event-driven microservices
  • Domain-driven design
  • CQRS

Stack Breakdown

API GatewayAuthNestJSExpressKafkaAnalytics

Architecture Layers

1Gateway
2Auth
3Domain Services
4Event Bus
5Analytics
6Error Isolation

Components by Category

backend

API GatewayAuth ServiceNestJSExpressNotification Service

async

KafkaQueue WorkerDead Letter Queue

database

PostgreSQLMongoDBClickHouse

Why This Topology Works

Kafka event bus decouples domain services, enabling independent deployment and scaling. Each service owns its data. Dead letter queue prevents cascade failures.

Scaling Notes

Each microservice scales independently. Kafka partitioning by entity key ensures ordered processing. Auth service caches tokens in Redis.

Observability

Distributed tracing across service boundaries. Kafka consumer lag monitoring. Per-service error rate dashboards.

Typical Bottlenecks

  • Service latency and timeout behavior on critical routes
  • Queue lag, retry storms, and DLQ growth during incidents
  • Write amplification and query contention on primary stores

Async Flow and Reliability

User-facing operations remain synchronous while long-running work moves through queues or streams. Workers consume jobs independently with retry and failure isolation, improving resilience under burst load.

Upgrade Path

Harden each domain with clear ownership, enforce SLO budgets, and adopt multi-region or active-passive failover where downtime costs are high.

Operating Envelope

Complexity is marked as Advanced with an intended scope of Org critical. Use this as a planning baseline before adapting the template to your reliability and team constraints.