API Fundamentals
/Advanced
Advanced Interview Questions
Definition
Deep-dive questions testing architectural understanding of caching, security exploits, microservices, and protocol limitations.
Explain Like I'm New
Interviewers are looking for Senior engineers who understand the hidden mechanics of the web. They will ask about Idempotency, JWT cryptographic signatures, and gRPC.
Real World Example
Being asked: 'Explain the OAuth 2.0 Authorization Code Flow.'
Common Use Cases
- •Senior Engineering Interviews
- •Backend Architect Roles
Terminal Output
bash / terminal
/*
Common Advanced Question:
"How does a JWT securely prove identity without a database lookup?"
Answer:
When the server creates the JWT, it hashes the Header + Payload together with a highly guarded SECRET_KEY. It appends this Hash to the end of the token as the Signature.
When the client sends the token back, the server re-runs the hashing algorithm on the Header + Payload using its secret key. If the result matches the Signature on the token, the server mathematically guarantees the payload was not tampered with, proving identity instantly without touching a database.
*/
Interview Questions
basic
- Explain the difference between Authentication and Authorization.
intermediate
- Why would a team choose GraphQL over REST?