gRPC interview questions — Hard
98 hard-level gRPC questions from our API Testing bank, each with the correct answer and an explanation of why it is correct.
This topic slice is available to practise but is not yet part of our indexed set.
What this covers
gRPC appears throughout API Testing interviews. At hard level, interviewers are typically checking depth under pressure — edge cases, failure modes, performance characteristics, and the trade-offs you accepted. Work through these, then explain your answer out loud; the second part is what interviews actually test.
4 example questions
1. Identify the INCORRECT statement about gRPC:
- A. GRPC reuses the standard HTTP status codes like 404 and 500 as its own.correct
- B. GRPC supports unary, server-streaming, client-streaming, and bidirectional-streaming calls.
- C. Binary Protobuf payloads are smaller and faster to parse than equivalent JSON.
- D. Server reflection allows tools to discover available services without proto files.
Why: The selected statement is false. The other options are accurate statements about gRPC.
2. Regarding gRPC, which of the following is a false statement?
- A. GRPC status codes (like UNAVAILABLE, DEADLINE_EXCEEDED) differ from HTTP status codes.
- B. GRPC services can never be discovered without the original proto files.correct
- C. GRPC supports unary, server-streaming, client-streaming, and bidirectional-streaming calls.
- D. Grpcurl is a command-line tool for invoking gRPC services, similar to curl for REST.
Why: The selected statement is false. The other options are accurate statements about gRPC.
3. Which of the following statements about gRPC is FALSE?
- A. GRPC uses Protocol Buffers as its default interface definition and serialization format.
- B. Server reflection allows tools to discover available services without proto files.
- C. GRPC reuses the standard HTTP status codes like 404 and 500 as its own.correct
- D. Deadlines/timeouts are first-class in gRPC and should be tested for correct handling.
Why: The selected statement is false. The other options are accurate statements about gRPC.
4. Which statement about gRPC is NOT correct?
- A. GRPC uses Protocol Buffers as its default interface definition and serialization format.
- B. GRPC status codes (like UNAVAILABLE, DEADLINE_EXCEEDED) differ from HTTP status codes.
- C. GRPC supports only simple unary request/response calls.correct
- D. Deadlines/timeouts are first-class in gRPC and should be tested for correct handling.
Why: The selected statement is false. The other options are accurate statements about gRPC.