Time Budget

Signals Interviewer Scores

• Problem-solving: did candidate reach optimal independently?
• Coding: clean, idiomatic, no bugs.
• Communication: think-aloud, asks vs. assumes.
• Verification: caught own bugs, tested edge cases.
• Speed: completed in time without rushing.

Narration Phrases

• "Let me restate to make sure I understand: [problem]."
• "My initial thought is [brute force]. Let me check the complexity."
• "That's O(n²). Can we do better? Maybe [hint at structure]."
• "I'll use [data structure] because [reason]. Trade-off: [cost]."
• "Let me code the main loop, then handle edges."
• "Tracing: input X → state at line N is Y → output Z."
• "Edge cases: empty, single, duplicates, negatives, overflow."

Collaborative Posture

• Treat interviewer as pair-partner, not adversary.
• Ask permission to skip: "Should I implement helper X or assume it's given?"
• Acknowledge hints: "Good point — let me reconsider."
• Don't argue if interviewer disagrees; explore their view.

Checklist

• Input shape: type, range, sorted?, can be empty?, can have duplicates / negatives / unicode?
• Output: format, single answer or all, modify in place?
• Constraints: n size, time/space limits.
• Ambiguity: how to break ties, undefined cases.
• API surface: can I assume helper X exists? stdlib OK?
• Examples: walk through the given one. Construct one of your own.

For System Design

• Functional requirements: top 3 features only. Cut nice-to-haves.
• Scale: DAU, requests/sec, data size, growth.
• SLA: latency, availability targets.
• Reads vs writes ratio.
• Consistency requirements: strong vs eventual.
• Tenancy: single user, multi-tenant, geo.

Stuck Recovery

1. Pause & restate the subproblem aloud.
2. Try simpler input (n=1, n=2). Look for pattern.
3. List candidate techniques (DP? Greedy? Graph?). Cross out infeasible.
4. If still stuck after 3 min: "Let me ask — am I on the right track with [approach]?"
5. Accept hint gracefully. Explicitly integrate: "OK so with [hint] I can now..."

When to Abandon Approach

• Approach won't fit complexity target → switch fast.
• Edge cases require special-cases stacking up → wrong abstraction.
• Implementation requires obscure data structure → simpler exists.
• Sunk-cost fallacy is real. State explicitly: "I'm going to switch to [Y] because [reason]."

Top 15

1. Coding before clarifying.
2. Silent thinking > 30 sec.
3. Jumping to optimal without stating brute force.
4. Not stating complexity until asked.
5. Not testing before declaring done.
6. Off-by-one in loop bounds.
7. Mutating input then iterating it.
8. Ignoring edge cases (empty, n=1, duplicates).
9. Using global state in recursion.
10. Defensive code that hides bugs (try/except swallow).
11. Premature abstraction (helper for one-line op).
12. Variable names: x, y, tmp.
13. Copy-paste blocks instead of loops.
14. Not handling interviewer's hint as a hint.
15. Ending with "I think it works" instead of trace.

Flow

Rules

• Never just name-drop tech. State why Kafka vs SQS, Postgres vs Dynamo.
• Numbers always. "Let's say 100M DAU, 10 RPS each = 1B writes/day = 12k WPS peak."
• Draw flow before storage. Storage choice falls out of access pattern.
• Acknowledge trade-offs. No silver bullets.
• Drive the depth — tell interviewer what you'd dive into next.

Pacing

• If story past 4 min, you've lost interviewer. Self-monitor with mental clock.
• Pause for follow-up — interviewer will drill where they want depth.
• Don't pre-empt every angle; leave hooks for them to pull.
• Always end with explicit lesson: "What I'd do differently is..."

Follow-up Patterns

Week Before

• Confirm tech stack expectations with recruiter.
• Block prep: 4–6 hr/day.
• 2 mock coding rounds (Pramp / interviewing.io / friend).
• 1 mock system design.
• 1 mock behavioral.
• Re-read company eng blog (2 recent posts).
• Prep 3 questions per round.

Day Of

• Sleep 8 hr night before. Don't cram.
• Light meal pre-loop. Caffeine if normal for you.
• 15 min before: mental warmup — solve one easy problem out loud.
• Have water + paper + pen.
• Quiet, well-lit room. Camera at eye level.
• Test mic + screen-share before start.
• Between rounds: stand, water, reset. Don't dwell on perceived flubs.

After

• Within 24 hr: thank-you note to recruiter (not interviewers directly unless invited).
• Self-debrief: write down questions, what went well/poorly.
• If rejected: ask recruiter for feedback. Some give specifics.

Rules

• Never share current comp until offer in hand. "I'm looking for competitive total comp."
• Never accept on the call. "Thanks — let me review with my partner / take 24–48 hr."
• Always ask for a written offer document before negotiating.
• Negotiate on total comp (base + bonus + equity + sign-on), not just base.
• Use competing offers as leverage. If none, market data (levels.fyi).
• Ask for ranges, not points: "Is there flexibility on equity?"
• Recruiter is not your enemy — they want to close. Help them help you.

Levers