Coding round playbook

Core details

Opening 4-step loop (≈3–5 minutes before heavy coding):

1. Restate goal + success criteria.
2. Constraints: input size, mutability, deterministic tie-break rules, time/space targets.
3. Micro-example on the board — 5–15 element instance.
4. Two approaches: baseline brute + target optimized; state asymptotics.

While coding: narrate invariant above tight loop; call edge cases aloud (empty, single, duplicates, negatives, overflow semantics if relevant).

Closing: propose tests (even if not typed) + complexity restatement + what you’d improve with 10 more minutes.

Understanding

Interviewers evaluate search process under uncertainty compressed into 45 minutes—they reward visible structure reducing hidden backtracking thrash. Complexity discussion is a proof obligation—silent coding until “done” forfeits half the signal.

Senior understanding

Tie answer to telemetry you’d add if productizing (sanity metrics on edge triggers) when problem maps to real system—signals staff thinking.

Diagram

See also

• System design playbook
• DSA hub