Build an API Gateway

onion middleware and response fan-out

Challenge 7 of Traffic & ResilienceAdvanced~65 min

The capstone of the web-infra family: a single front door that routes requests to backend services by prefix, forwards them through a pluggable transport, runs a middleware pipeline (onion model), enforces API-key auth, and fans out to aggregate several services into one response.

5 steps

1. 1The Routing Table
2. 2Forwarding Requests
3. 3The Middleware Pipeline
4. 4Auth Middleware
5. 5Response Aggregation