Interview Debugging & Implementation — Reproduce, Trace, Fix, Ship
Studies in this cluster, in series order. Each one keeps its own URL.
Engineering practices
Timed interview debugging: find the signal, reproduce, ship the smallest fix, then design one component.
- 1.Interview Debugging & Implementation — Reproduce, Trace, Fix, ShipTimed interview loop: clarify, hypothesize, evidence, fix, verify, then a feature or one-component LLD. Logs versus a debugger versus reading code cold.
- 2.Finding the Signal — CloudWatch, Traces & Correlation IDsCloudWatch Logs Insights query craft, alarms as pointers, and X-Ray or OpenTelemetry correlation. The same loop on Cloud Logging and kubectl.
- 3.Reproduce & Hypothesize — Narrow, Bisect & Local ReproTighten the window and the tenant, change one variable, and keep a hypothesis log. Git bisect is named at a high level and taught in the Git series.
- 4.Fix, Verify & Roll Back — Smallest Change & ProofThe smallest correct diff, a characterization test, proof that the same query went quiet, and a rollback with a blast radius.
- 5.Implement the Feature in the Same SessionTurn a vague also-add-X into a contract: inputs, errors, idempotency, and the edges you will not build in the remaining time.
- 6.Low-Level Design Under Time — Interfaces, State & TradeoffsIn-interview low-level design for one component: interfaces, invariants, where state lives, and failure. A request-scoped log correlator, with a payment state handler as the same moves.