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Product Builder 面試日練

A daily product builder interview drill rotating through seven topics by day of the week — product sense, metrics, strategy, AI product design, growth, technical PM, and behavioral — pulling the latest case studies and interview questions from the web.

Product Builder Interview Prep — 2026-08-20: Strategy & Execution

Strategy interviews don't test whether you can recite Porter's Five Forces — they test whether you can make well-reasoned trade-offs with incomplete information and convince others. Today we practice market positioning analysis, moat assessment, roadmap prioritization defense, and stakeholder alignment communication.

Product Builder Interview Prep — 2026-08-21: Growth & Experimentation

The dividing line in growth interviews is whether you're talking about linear improvement or compound loops — adding an acquisition channel is marketing; making one user bring in two users is growth. Today we practice the Goal → Metric → Bottleneck → Hypothesis → Experiment → Measurement six-step diagnosis framework, with a question drawn from a real OpenAI Growth PM take-home.

Product Builder Interview Daily — 2026-08-22: Technical PM

Technical PM interviews don't test whether you can draw architecture diagrams — they test whether you clarify constraints before drawing. Today we practice the Clarify → Estimate → Sketch → Trade-off → Mitigation structure on a real Google interview question ('Design Google Keep for enterprise'), with a case study of an Uber PM navigating a latency vs. consistency trade-off.

Product Builder Interview Daily — 2026-08-23: Behavioral & Weekly Review

Behavioral interviews don't test whether you have stories — they test whether you pick the right one. The same 'I screwed up' experience can read as a Failure Story or a Problem Story, and choosing wrong makes you look like you're deflecting instead of owning. Today we practice the STAR-R framework (STAR plus a Reflection step), tackle an 'influencing without authority' prompt, and walk through a real case where an e-commerce PM killed a promised revenue feature four weeks before Black Friday to fix system stability instead.

Product Builder Interview Daily — 2026-08-24: Product Sense

Product Sense interviews don't test how many features you can brainstorm — they test whether you can turn a vague prompt into a behavior-driven diagnosis. In a real Google HC debrief, a candidate who pitched 12 YouTube features got rejected because 'they described what, not why.' Today we use the CIRCLES framework to break down a senior-user search experience problem, with Superhuman's story of raising their product/market fit score from 22% to 58% using a four-question survey as our case study.

Product Builder Interview Daily — 2026-08-25: Metrics & Analytics

Analytics interviews don't test whether you can write SQL — they test whether you can untangle contradictory signals like 'DAU is rising but advertisers are fleeing.' In a real Google hiring committee debrief, a candidate was rejected for treating 'DAU' as the North Star metric for News — the committee wanted a metric tied to business risk, not the prettiest number on the dashboard. Today we use a metric tree to break down exactly this kind of problem, with the legendary 'Google changed a font color and made a billion dollars' as our case study.

Product Builder Interview Daily — 2026-08-26: Strategy & Execution

Strategy questions don't test whether you can recite Porter's Five Forces — they test whether you can articulate a clear trade-off when you know you can't win on scale. Facing Google AI Overviews' 2 billion MAU and OpenAI Atlas, Perplexity chose to shut down its ad business entirely in early 2026 — a move that looks like self-inflicted revenue loss, but is exactly the kind of strategic coherence today's practice is about. Use TAM-SAM-SOM to frame the market, Five Forces to identify the battles you can't win, then answer 'What are you willing to sacrifice?'

Product Builder Interview Daily — 2026-08-27: AI Product Design

The question that trips people up most in AI product interviews isn't 'do you understand LLMs' — it's 'when the model is guaranteed to make mistakes, how do you design a system so those mistakes don't erode user trust.' Today we use Riddhi Bhasker's four-layer framework (Memory/Retrieval/Reasoning/Control) to think about human-in-the-loop as infrastructure design, and look at how Intercom lets AI auto-approve 19% of pull requests while still holding the line on quality.

Product Builder Interview Daily — 2026-08-28: Growth & Experimentation

The most common trap in Growth PM interviews isn't running out of growth ideas — it's jumping to a solution that 'obviously should work' before diagnosing the actual bottleneck. Today we swap Reforge's linear funnel thinking for Growth Loops, use a six-step diagnostic chain to find the real leak, and look at a real JobLeads experiment that cut 22 steps down to 5 — and changed nothing — to see why experiment velocity beats any single home run.

Product Builder Interview Daily — 2026-08-29: Technical PM

A Technical PM interview isn't testing whether you can code — it's testing whether you can turn a technical decision, like whether to accept an API breaking change, into a judgment call an engineer would actually respect. Today practices a real API versioning question using a four-step framework (clarify, sketch, break down trade-offs, tie back to product) plus a lightweight ADR, and compares it against how Stripe used idempotency keys to turn 'will a network retry cause a duplicate charge' from an open question into a written contract.

Product Builder Interview Daily — 2026-08-30: Behavioral & Weekly Review

A Behavioral interview isn't testing whether you have a great story — it's testing whether the committee can answer 'will this person get better over time' after hearing it. Today practices an influencing-without-authority scenario using the STAR-R framework (Situation-Task-Action-Result-Reflection), built around a real Amazon L5 PM debrief where the committee argued for 18 minutes and rejected a candidate who couldn't clearly explain how they handled cross-functional resistance. Wraps up with a seven-day weekly review and next week's prep direction.