SitePoint10 min readintermediate
Building Event-Driven Enterprise Applications with . NET and AWS
Summary
A practical guide to refactoring a monolithic onboarding API into an event‑driven architecture using ASP.NET Core, AWS SNS/SQS (or EventBridge), the outbox pattern, and idempotent consumers, with concrete code snippets and operational tips.
- Separate commands (synchronous) from events (asynchronous) to decouple services.
- Use SNS for fan‑out publishing and SQS queues per consumer for durable buffering and independent scaling.
- Avoid dual‑write bugs by persisting events to an Outbox table within the same DB transaction as the business change, then publishing asynchronously.
- Implement consumers as BackgroundService (or Lambda) that poll SQS, handle messages idempotently (store EventId), and respect visibility timeouts and DLQs.
Shows a realistic migration path from a tightly‑coupled request‑per‑operation flow to a resilient, scalable event‑driven system, highlighting pitfalls (dual‑write, duplicate processing) that only surface in production.
6/10
