What problem does an API gateway solve?
PICTURE THIS: DOM IS A TREE
Simple meaning
It is a single entry point for auth, TLS, rate limits, and routing to many backend services.
WHY — Microservices instead of guessing?
Why interviewers care about Microservices:
who only read docs from people who shipped.
and tied to Backend work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1It is a single
entry point for auth, TLS, rate limits, and routing to many backend services.
- 2Clients talk to one
host instead of discovering every microservice.
- 3It must not become
a giant business-logic dump
- 4keep domain rules in
the services.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
It is a single entry point for auth, TLS, rate limits, and routing to many backend services. Clients talk to one host instead of discovering every microservice.