Product sense
The Design Ladder
- 1Frame. Ask what would change the design, state the rest, set a goal for the company and the user, and say your route.
- 2Person. List two to four user groups by what they are trying to do. Pick one and say why.
- 3Pain. Walk through before, during and after the task. Rank pains by how often they happen and how much they hurt.
- 4Options. Offer three kinds of fix: near (the obvious one), far (ambitious) and sideways (a different angle).
- 5Bet. Score the options on value, effort and risk. Pick one and say what you give up.
- 6Proof. One headline metric, two helpers that explain it, one guardrail you refuse to harm.
- 7Walk down. Read your six commitment sentences back in order. That is your summary.
The mistake that costs most: Naming features in the first minute, before a user or a pain. Nothing was chosen, so there is no judgment to score.
Free lesson: The framework in one page
Metrics: pick the metric
Value Moment
- 1Name the value. Who gets what from the product, in one sentence. Name both sides of a marketplace.
- 2Find the moment. The action that shows a user just got that value, not that they opened the app.
- 3Make it a number. Decide what you count, over what window and with what qualifier. Match the window to how often the value happens.
- 4Stress-test it. Does it rise only with real value? Can a team game it? Does it lead revenue and retention? Will it move within weeks?
- 5Guard it. Add one to three guardrails that catch the damage if a team chases it too hard.
The mistake that costs most: Reaching for revenue, sign-ups or plain daily users by reflex. They lag, only ever go up, or count opens that gave nobody anything.
Free lesson: Choosing a north-star metric
Metrics: diagnose a change
Change Drill
- 1Check it’s real. Rule out logging, pipeline and definition changes before you hunt for causes.
- 2Size it. Measure how large it is, when it started, whether it was a step or a slide, and which other numbers moved.
- 3Slice it. Split by platform, region, user type and the metric’s parts until you find where the change lives.
- 4Line up suspects. Internal changes (releases, experiments, prices) and external ones (season, competitors, OS updates) that fit the timing and the slice. Rank them.
- 5Settle it. Name the likeliest cause, how you would prove it, what you would do, and whom you would tell.
The mistake that costs most: Guessing at causes (a competitor, the weather) before checking the drop is real and finding where it lives.
Free lesson: Choosing a north-star metric
Estimation
The five-step estimate
- 1Clarify. Pin down the unit, the place, the time period and what counts.
- 2Structure. Say and write the equation before any number goes in.
- 3Assume. A round number for each part, each with a one-line reason.
- 4Calculate. Multiply out loud, round as you go, and give the answer to one or two significant figures.
- 5Check. Test it from a second route (supply side, per person, an analogy) and name the assumption that moves it most.
The mistake that costs most: Multiplying numbers as they occur to you before the equation is set, then skipping the check, so a tenfold error goes unnoticed.
Free lesson: The approach in five steps
Behavioral
The five-beat story
- 1Headline. Answer the question and give away the ending in one or two sentences.
- 2Stakes. Two or three sentences: your role, the situation and what was on the line.
- 3Moves. The two to four decisions you made and why, plus one path you chose not to take.
- 4Result. What changed, with a number, and what didn’t work.
- 5Lesson. The takeaway, and a later moment when you put it to use.
The mistake that costs most: A minute of company background before anything happens, then “we” all the way through, so the interviewer can’t tell which decisions were yours.
Free lesson: What behavioral rounds test
Product strategy
The Spoken Memo
- 1Decision. Restate the prompt as a decision with a goal, a time frame and constraints.
- 2Ground. Look through three lenses (customers, market, us) and label your assumptions.
- 3Options. Three or four real options, always including a baseline such as staying the course.
- 4Call. Compare them on customer value, right to win, and prize versus cost and risk. Pick one.
- 5Proof. The top risks, a cheap test for each, and the result that would make you stop.
The mistake that costs most: A tour of everything you know (market size, a SWOT grid, five competitors) with no decision at the end.
Free lesson: How to approach a strategy question
Technical
Goal, Path, Pressure, Call
- 1Goal. What the system is for, in user terms, plus one or two questions about scale or scope.
- 2Path. Trace the main flow from the user’s action to the result, in boxes and arrows, not code.
- 3Pressure. Where it strains. Pick the two or three of scale, speed, failure, cost, abuse and privacy that matter here.
- 4Call. Decide the key trade-off, say what you give up and how you would know it worked.
The mistake that costs most: A jargon dump (microservices, queues, a named database) with no user, no flow and no decision. Know everything you say one level deeper than you say it.
Free lesson: What technical rounds test
AI product
The Five Gates
- 1Job. Who the user is, the task, and what a good outcome looks like for them.
- 2Fit. Is AI the best tool here? Which capability: generate, summarize, extract, classify, search or act?
- 3Failure. When the model is wrong, what happens, and how the design catches, shows or recovers from it.
- 4Proof. What you test before launch and what you measure once real users arrive.
- 5Ship. Cost, speed, what could go badly wrong, and how you roll it out. For a metric drop, walk the gates in reverse.
The mistake that costs most: Designing only the happy path: talking about metrics before saying what happens when the model gets it wrong.
Free lesson: What AI product rounds test