Broken code. Fix it. 10
Production bugs with the artifacts you'd see on call — failing test, log excerpt, broken code. Identify the root cause, fix it, compare against the canonical solution.
Backend debugging interview practice, answered
A debugging interview hands you broken, production-shaped code and a failing test, then watches how you isolate the root cause under time pressure. Senior Loop's bug catalog is built from real incident patterns — race conditions, silent precision drift, retry storms, broken idempotency — across payment systems, APIs, and distributed backends, each with AI-graded feedback on your diagnosis, not just whether the test passes.
What is a backend debugging interview?+−
Instead of a whiteboard algorithm, you're given real, broken production-style code and a failing test, and asked to find and explain the root cause the way you would during an actual incident.
How is this different from LeetCode-style prep?+−
LeetCode tests algorithm recall in isolation. These bugs test root-cause reasoning in realistic backend systems — the skill senior and staff loops actually screen for, graded against a rubric of the real underlying failure.
What kinds of bugs are included?+−
10+ real production bugs spanning payment systems, distributed systems, and APIs — race conditions, idempotency failures, precision drift, and other issues senior engineers are expected to catch fast.
Is debugging practice free?+−
Yes — 3 bug hunt exercises are free with no card required.