Business rules that scatter across routers, schemas and models are a domain problem, not a FastAPI one. Here's how Evans' own layered architecture fixes it, one bounded context at a time.
The simplest event-driven design is never the finished one. This post builds an order fulfillment system one design change at a time, each one fixing a concrete failure the last couldn't, from a synchronous handler to a production-ready, choreographed architecture.
Why your HTTP endpoint shouldn't talk to Kafka directly, how a consumer fits inside FastAPI's event loop, and why Kubernetes pods don't remember what they just learned.
HTTP was built so a client asks and a server answers. This post follows the 30-year fight to make the server speak first, from refreshing a page to WebSockets, and shows when each technique is the right one.
I understood SOLID for years and still couldn't explain it when asked. Here is the story behind it, the rot it fights, how to spot good and bad usage in code, and how to finally make it stick.