Edge and reliability / Intermediate / 9 min
API gateway with Nginx
Routing, TLS, JWT auth, rate limits, caching and failover, with a live nginx.conf you can copy.
Start the simulation → Change the load, break a part, watch what happens. Free, no sign-up.
In short
- What it is
- An API gateway is the single front door: it checks auth, applies rate limits, may cache, and routes each request to the right service.
- Why it matters
- Shared rules live in one place instead of being copied into every service.
- The trade-off
- It is a single point of failure and an extra hop, so it must be run as several copies and kept thin.
- Say it in an interview
- "The gateway handles auth, rate limiting and routing, so services only contain business logic."
Check yourself
Where is the TLS connection usually terminated in this setup?
Answer: At the gateway (Nginx). The gateway decrypts HTTPS once; internal hops can then use plain HTTP or their own mTLS.
What does Nginx’s auth_request do?
Answer: Asks an auth service to approve each request before proxying it. Requests without a valid token get 401 at the edge and never reach your services.
An upstream server crashes and proxy_next_upstream is on. What does the client see?
Answer: Usually a success, because Nginx retries on the other server. Nginx retries the failed request on another server in the upstream, hiding the failure.