gRPC — Part 3: Advanced Concepts & Interview Q&A

What is this?

You understand the phone-extension idea now — call a remote method like a local function, contract-first via .proto, binary over HTTP/2. This part is the mock interview. We'll sit on the other side of the table, decode what each question is really probing, build a model answer, and end each one with the senior line — the single sentence that signals you've actually run this in production, not just read about it.

The one-line idea: interviewers don't want the gRPC marketing sheet. They want to see you reason about the trade-offs — when gRPC earns its complexity, where it hurts (the browser), and how you keep long-lived connections, evolving schemas, and tight deadlines from biting you.

First, a quick tour of the advanced features and anti-patterns these questions lean on, then the Q&A.