Full-Stack Problem Diagnosis Questions

Systematic methods for isolating and diagnosing problems that span the client, application programming interfaces, services, databases, and infrastructure. Topics include validating network calls and request payloads, comparing expected and actual contracts, analyzing database query plans, using logs and distributed traces to follow request flows, reproducing issues locally or in staging, and proposing fixes and regression tests. Interviewers assess the candidate's ability to reason across layers, choose diagnostic tools, and communicate findings and next steps clearly.