← Back to academy

4 weeks

4-Week Interview Sprint

Highest-yield drills for an active mid-senior frontend loop.

Audience

Engineers with interviews scheduled or likely within a month.

Outcome

Ship with a crisp pitch, runnable JS/React reps, system design structure, and mock-loop readiness.

Practice Items

147 questions

Format Mix

Debugging · 27 JS Function · 60 UI Component · 26 React App · 5 React Hook · 1 System Design · 8 Behavioral · 19 Portfolio · 1

Practice Sequence

01Design JavaScript runtime orderingShows whether you understand javascript runtime ordering as an operating model, not as memorized trivia.DebuggingMid30m 02Senior tradeoff JavaScript runtime orderingShows whether you understand javascript runtime ordering as an operating model, not as memorized trivia.DebuggingSenior35m 03Design Promise failure propagationShows whether you understand promise failure propagation as an operating model, not as memorized trivia.DebuggingMid30m 04Senior tradeoff Promise failure propagationShows whether you understand promise failure propagation as an operating model, not as memorized trivia.DebuggingSenior35m 05Design Closure lifetime and memoryShows whether you understand closure lifetime and memory as an operating model, not as memorized trivia.DebuggingMid30m 06Senior tradeoff Closure lifetime and memoryShows whether you understand closure lifetime and memory as an operating model, not as memorized trivia.DebuggingSenior35m 07Design Objects, prototypes, and classesShows whether you understand objects, prototypes, and classes as an operating model, not as memorized trivia.DebuggingMid30m 08Senior tradeoff Objects, prototypes, and classesShows whether you understand objects, prototypes, and classes as an operating model, not as memorized trivia.DebuggingSenior35m 09Design TypeScript narrowingShows whether you understand typescript narrowing as an operating model, not as memorized trivia.DebuggingMid30m 10Senior tradeoff TypeScript narrowingShows whether you understand typescript narrowing as an operating model, not as memorized trivia.DebuggingSenior35m 11Design Generic API modelingShows whether you understand generic api modeling as an operating model, not as memorized trivia.DebuggingMid30m 12Senior tradeoff Generic API modelingShows whether you understand generic api modeling as an operating model, not as memorized trivia.DebuggingSenior35m 13Design HTML semantics and formsShows whether you understand html semantics and forms as an operating model, not as memorized trivia.DebuggingMid30m 14Senior tradeoff HTML semantics and formsShows whether you understand html semantics and forms as an operating model, not as memorized trivia.DebuggingSenior35m 15Design CSS layout mechanicsShows whether you understand css layout mechanics as an operating model, not as memorized trivia.DebuggingMid30m 16Senior tradeoff CSS layout mechanicsShows whether you understand css layout mechanics as an operating model, not as memorized trivia.DebuggingSenior35m 17Design Accessibility interaction modelShows whether you understand accessibility interaction model as an operating model, not as memorized trivia.DebuggingMid30m 18Senior tradeoff Accessibility interaction modelShows whether you understand accessibility interaction model as an operating model, not as memorized trivia.DebuggingSenior35m 19Design Browser networking and securityShows whether you understand browser networking and security as an operating model, not as memorized trivia.DebuggingMid30m 20Senior tradeoff Browser networking and securityShows whether you understand browser networking and security as an operating model, not as memorized trivia.DebuggingSenior35m 21Implement debounce with cancel and flushTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 22Harden debounce with cancel and flushTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 23Test debounce with cancel and flushTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 24Narrate debounce with cancel and flushTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 25Implement throttle with trailing callsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 26Harden throttle with trailing callsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 27Test throttle with trailing callsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 28Narrate throttle with trailing callsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 29Implement memoize with cache invalidationTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 30Harden memoize with cache invalidationTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 31Test memoize with cache invalidationTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 32Narrate memoize with cache invalidationTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 33Implement deep clone with cyclesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 34Harden deep clone with cyclesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 35Test deep clone with cyclesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 36Narrate deep clone with cyclesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 37Implement deep equality with arrays and objectsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 38Harden deep equality with arrays and objectsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 39Test deep equality with arrays and objectsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 40Narrate deep equality with arrays and objectsTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 41Implement flatten nested arraysTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 42Harden flatten nested arraysTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 43Test flatten nested arraysTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 44Narrate flatten nested arraysTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 45Implement groupBy with stable orderingTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 46Harden groupBy with stable orderingTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 47Test groupBy with stable orderingTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 48Narrate groupBy with stable orderingTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 49Implement compose and pipeTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 50Harden compose and pipeTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 51Test compose and pipeTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 52Narrate compose and pipeTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 53Implement event emitter with once and offTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 54Harden event emitter with once and offTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 55Test event emitter with once and offTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 56Narrate event emitter with once and offTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 57Implement promise pool concurrency limiterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 58Harden promise pool concurrency limiterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 59Test promise pool concurrency limiterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 60Narrate promise pool concurrency limiterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 61Implement retry with abort and jitterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 62Harden retry with abort and jitterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 63Test retry with abort and jitterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 64Narrate retry with abort and jitterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 65Implement timeout wrapper for promisesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 66Harden timeout wrapper for promisesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 67Test timeout wrapper for promisesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 68Narrate timeout wrapper for promisesTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 69Implement least-recently-used cacheTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 70Harden least-recently-used cacheTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 71Test least-recently-used cacheTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 72Narrate least-recently-used cacheTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 73Implement query string parserTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 74Harden query string parserTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 75Test query string parserTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 76Narrate query string parserTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 77Implement object path getter and setterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid30m 78Harden object path getter and setterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionMid35m 79Test object path getter and setterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior35m 80Narrate object path getter and setterTests whether you can turn a familiar utility into a precise contract instead of coding only the happy path.JS FunctionSenior40m 81Build an accessible modal dialogShows whether you can build components as interaction systems rather than visual boxes.UI ComponentMid45m 82Build a combobox autocompleteShows whether you can build components as interaction systems rather than visual boxes.UI ComponentMid45m 83Build a multi-select listboxShows whether you can build components as interaction systems rather than visual boxes.UI ComponentMid45m 84Build a sortable data tableShows whether you can build components as interaction systems rather than visual boxes.UI ComponentMid45m 85Build a virtualized feedShows whether you can build components as interaction systems rather than visual boxes.UI ComponentMid45m 86Build a file explorer treeShows whether you can build components as interaction systems rather than visual boxes.UI ComponentMid45m 87Build a toast notification systemShows whether you can build components as interaction systems rather than visual boxes.UI ComponentSenior60m 88Build a tabs with keyboard navigationShows whether you can build components as interaction systems rather than visual boxes.UI ComponentSenior60m 89Implement useState derivation in a product componentShows whether you can explain React behavior while building maintainable product UI.React AppMid40m 90Implement useEffect cleanup in a product componentShows whether you can explain React behavior while building maintainable product UI.React AppMid40m 91Implement useReducer state machines in a product componentShows whether you can explain React behavior while building maintainable product UI.React AppMid40m 92Implement useMemo and useCallback boundaries in a product componentShows whether you can explain React behavior while building maintainable product UI.React AppMid40m 93Implement custom useQuery hook in a product componentShows whether you can explain React behavior while building maintainable product UI.React HookMid40m 94Implement optimistic updates in a product componentShows whether you can explain React behavior while building maintainable product UI.React AppMid40m 95Design an autocomplete searchShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 96Design an enterprise data tableShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 97Design a rich text editorShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 98Design a collaborative document editorShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 99Design a news feedShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 100Design a chat applicationShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 101Design a notification centerShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 102Design a dashboard builderShows whether you can turn a broad product surface into a durable frontend architecture with clear contracts.System DesignSenior50m 103Practice: unit test a reducer with illegal transitionsShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingMid35m 104Practice: mock server states with MSWShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentMid35m 105Practice: write Playwright reload recoveryShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentMid35m 106Practice: profile a slow React renderShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentMid35m 107Practice: debug a hydration mismatchShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingMid35m 108Practice: measure Core Web Vitals regressionShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentMid35m 109Practice: test keyboard navigationShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentMid35m 110Practice: verify screen reader namesShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentMid35m 111Practice: write visual regression statesShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingSenior45m 112Practice: debug a memory leak from listenersShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 113Practice: trace duplicate network requestsShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 114Practice: build a browser storage migration testShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 115Practice: audit bundle size growthShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingSenior45m 116Practice: debug stale cache dataShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 117Practice: test optimistic update rollbackShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 118Practice: create incident notes for frontend outageShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 119Practice: instrument client error loggingShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingSenior45m 120Practice: design feature flag cleanup testsShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 121Practice: load test polling behaviorShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 122Practice: verify CSP and XSS boundariesShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 123Practice: triage flaky E2E testsShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingSenior45m 124Practice: write component contract testsShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 125Practice: debug race conditions in searchShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 126Practice: profile virtualized list jankShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.UI ComponentSenior45m 127Practice: test form validation accessibilityShows whether you can prove frontend behavior instead of relying on screenshots or manual confidence.DebuggingSenior45m 128Prepare two-minute frontend senior pitchShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 129Prepare resume project narrativeShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 130Prepare migration leadership storyShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 131Prepare performance impact storyShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 132Prepare conflict with product or designShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 133Prepare debugging incident storyShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 134Prepare mentoring and code review storyShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 135Prepare first 30 days in a new frontend teamShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralMid30m 136Prepare first 90 days execution planShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior30m 137Prepare reverse questions for platform teamShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior30m 138Prepare reverse questions for product teamShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior40m 139Prepare salary and role-leveling discussionShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior40m 140Prepare take-home project scopingShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior40m 141Prepare live coding narrationShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior40m 142Prepare system design opening scriptShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior40m 143Prepare tradeoff language practiceShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralSenior40m 144Prepare unknown-domain ramp-up answerShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralStaff40m 145Prepare failure and learning storyShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralStaff40m 146Prepare staff-leaning leverage storyShows whether your communication matches the level of ownership expected from senior frontend engineers.BehavioralStaff40m 147Prepare portfolio README reviewShows whether your communication matches the level of ownership expected from senior frontend engineers.PortfolioStaff40m