APIs & Networking Interview Questions
API and networking questions cover interface design, load balancing, rate limiting and the request path from client to service.
The API and networking layer is where a design meets its clients: how requests are routed, how load is spread across instances, how abusive traffic is throttled, and what the interface actually looks like. It is often the first thing an interviewer asks you to sketch, because it forces the requirements to become concrete.
What interviewers probe
Rate limiting is the highest-frequency topic here and the algorithms carry different behaviour — a fixed window allows a burst at the boundary that a sliding window does not, and a token bucket permits controlled bursts on purpose. Interviewers also probe where the limiter lives and how it stays consistent across instances. On load balancing, knowing when routing must inspect the request rather than only the connection is the detail that comes up.
Practice apis & networking
5 system design · 1/3/1 easy/medium/hard
APIs & Networking interview questions — FAQ
Which rate limiting algorithm should I name?
Token bucket when controlled bursts are acceptable, sliding window when a strict rate must hold across boundaries. Say where the counter lives, since a limit enforced per instance is not the limit you promised.
What makes an API design answer strong?
Naming the resources, the operations, what is idempotent, and how errors and pagination work. Idempotency in particular is what makes client retries safe, and it connects directly to the delivery guarantees elsewhere in the design.