Concept guides.
Interactive tutorials on the ideas behind the questions. Learn the concept, then practice the questions built on it. Every guide is free with an account, no card needed.
Coach note
Every guide here is free with an account, no card needed, and we will point you at the ones that match your role. Get Free Account, or sign in.
AI, data & design
Entry · Mid · Senior- Accessibility basics: keyboard, contrast, announceThe accessibility checks interviewers probe for: full keyboard operability with a sane focus order, what a screen reader actually announces, never en…
- Catching AI's confident mistakesHow to verify AI output without re-doing the work: triage what to check first (names, numbers, dates, quotes, citations — the checkable claims), reco…
- Debugging as hypothesis testingThe method behind every 'walk me through your investigation' answer: reproduce first, ask what changed, form a hypothesis that a cheap probe can fals…
- Every screen has six statesThe state grid behind every flow-design answer: empty, loading, partial, success, error, offline — plus error-message anatomy (what happened, why, wh…
- Joins that keep the right rowsHow each join type decides which rows survive: INNER drops non-matches, LEFT keeps every left row with NULL padding (the 'including customers who nev…
Business & analytical
Entry · Mid · Senior- A/B test design: hypothesis, randomization, primary metricTurning 'make the homepage better' into a runnable experiment: a falsifiable hypothesis (change X moves metric Y by Z for population P), random assig…
- Fermi estimation: decompose, anchor, sanity-checkThe four-step Fermi method: break the unknown into factors you can anchor (population, frequency, price), multiply through, round to one significant…
- Funnel metrics and conversion decompositionOverall conversion is a product of stage rates: visit → sign-up → activation → paid
- Market sizing: top-down vs bottom-upTwo independent routes to a market number: top-down (population × penetration × spend) and bottom-up (units × usage × price), and why running both an…
- Metric anomaly triage: real move or artifact?The first-hour checklist before believing any metric move: normal variance and seasonality (was it a holiday? within 2σ?), then instrumentation (trac…
Education & teaching
Entry · Mid- Backward design: objective, evidence, then activitiesWiggins & McTighe's backward design: write a Bloom's-verb objective describing what students will do by the end, decide what evidence (formative and…
- Checking for understanding — and acting on itFast formative checks that beat 'does everyone get it?' — cold call, whiteboards, think-pair-share, exit tickets — and the decision rule afterward: m…
- De-escalation in the momentThe escalation curve (trigger, agitation, peak, recovery) and the moves that lower the temperature: calm voice, space, removing the audience, naming…
- I do, we do, you do: the lesson arcThe gradual-release arc — model with a worked example, practice together, release to independent work — plus chunking to manage cognitive load, and w…
- Openings that earn attentionHow to design the first three minutes of a lesson: hook types (puzzling case, prediction, relevance bridge, cold artifact), why 'today we will learn'…
Healthcare & clinical
Entry · Mid · Senior- Aviate, navigate, communicate: task priority in an emergencyThe aviate-navigate-communicate hierarchy for emergencies: fly the aircraft first, establish where you're going second, and only then talk — plus how…
- Confidentiality and its limitsConfidentiality is the default, with defined exits: disclosure with patient consent, mandated public-health and safety reporting, imminent risk to se…
- Hypothesis-driven history and the differentialHow clinicians build a differential diagnosis: generate hypotheses early from the presenting complaint, then ask history questions that discriminate…
- Informed consent: the elements that make it validThe elements of valid consent — disclosure of nature, material risks, benefits, and alternatives (including doing nothing), decision-making capacity,…
- Memory items and QRH checklist disciplineHow emergency procedures split into immediate-recall memory items and read-do QRH checklists: confirm you're on the right checklist, run challenge-re…
Legal & policy
Entry · Mid · Senior- BLUF: the one-page decision briefBottom line up front: the recommendation and the ask live in the first sentence, then a fixed skeleton — two lines of context, three evidence-backed…
- Issue-spotting sweep: parties, duties, breaches, remediesThe systematic sweep behind IRAC: list every party and relationship, ask what duty each owed (contract, tort, statute, fiduciary), where it was breac…
- Stakeholder mapping: who's affected, who decides, who fightsA systematic stakeholder enumeration — targets, implementers, funders, enforcers, and the adjacent winners and losers people forget — placed on a pow…
- Translating for non-experts: plain-language summariesHow to turn a dense clause or technical finding into something a busy non-expert can act on: lead with what it means for the reader, swap abstraction…
- Comparing policy options with a criteria matrixThe core policy-shop move: generate genuinely different options — status quo, tax vs ban vs subsidy vs mandate vs disclosure, narrower targeting — th…
Marketing & sales
Entry · Mid- Campaign brief anatomy: audience, insight, message, measurementThe four load-bearing slots of a brief — a sharply defined audience segment, the human insight underneath, one single-minded message, and how success…
- Closed loops and shared mental modelsClosed-loop communication — command, readback, hearback — plus standard callouts, briefings, and explicit transfer of controls as the machinery that…
- Discovery questions that ladder to impactSPIN-style laddering — situation, problem, implication, need-payoff — using open-ended questions that climb from symptom to quantified business impac…
- Positioning statements and proof pointsThe classic positioning template — for (audience), who (need), our (product) is the (category) that (benefit), unlike (alternative) — and pairing eve…
- Speaking up: graded assertiveness in the cockpitThe graded-assertiveness ladder (probe, alert, challenge, declare — PACE) and the two-challenge rule: how a junior crew member escalates a safety con…
Operations & industrial
Entry · Mid · Senior- Bottlenecks & queues: why waits explode near capacityTheory of constraints — the slowest step sets system throughput, so exploit then elevate the constraint (and expect it to move) — plus the queueing i…
- Checklists, runbooks & the pre-shift briefingWhy high-pressure operations run on written procedure: checklists catch the errors experts make under load, runbooks turn a recurring failure into a…
- Lean diagnosis: eight wastes & value-stream mapsMap the current state before changing anything: draw the value stream, classify each step as value-added vs non-value-added, spot the eight wastes (w…
- Loads, margins & factors of safetyDead, live, and environmental loads combine into the demand a structure must beat with margin: the factor of safety covers uncertainty in loads, mate…
- RevPAR & rate fences: selling the same room at many pricesRevPAR = ADR x occupancy, so rate and volume trade against each other — and yield management beats one-price by segmenting demand (business vs leisur…
People & leadership
Entry · Mid · Senior- Ending a hard call with next stepsThe last ninety seconds carry the call
- Escalating well: when to raise it and howA three-factor test for when to escalate — irreversibility, blast radius, and whether the decision is yours to own — and the mechanics of doing it wi…
- Five conflict styles and when each winsThe Thomas–Kilmann grid — competing, collaborating, compromising, avoiding, accommodating — as positions on assertiveness × cooperativeness, and matc…
- SBI: feedback that names behavior, not characterThe Situation–Behavior–Impact structure: anchor feedback to a specific moment, describe observable behavior instead of traits, state the impact you s…
- STAR and CARL: structuring your storyThe four-beat STAR arc (Situation, Task, Action, Result) for any 'tell me about a time' question, and the CARL variant (Context, Action, Result, Lear…