Frontend Fundamentals8 Problems
Vanilla JavaScript, DOM manipulation, CSS layout, event handling, and UI behavior. The core mechanics that every frontend engineer needs wired in before anything else.
Start Track →Pick a track. Start the reps.
Each track is a focused set of problems around one domain. Work through them in order or jump between tracks. The practice loop is the same either way.
React6 / 7 Problems
Components, state, effects, and data flow. Build, debug, and extend real React applications starting from working starter code, not blank files.
Start Track →Backend Basics5 / 8 Problems
Python, rate limiting, caching, config handling, and server-side logic. Write code that deals with real constraints, not just the happy path.
Start Track →Algorithms & Data StructuresSoon
Arrays, trees, graphs, sorting, and dynamic programming. Classic computer science fundamentals with practical framing instead of pure whiteboard exercises.
8 problems plannedSecuritySoon
Authentication, input validation, common vulnerabilities, and writing code that handles untrusted data without falling apart. Cross-cutting across every track.
4 problems plannedTestingSoon
Write test suites for real code, find gaps in coverage, and debug intentionally broken implementations by writing tests. You bring the tests, the problems bring the bugs.
4 problems plannedFull StackSoon
End-to-end features from database to UI. Problems that require thinking across layers and making real tradeoffs about where logic should live.
4 problems plannedSystem DesignSoon
Broader architecture cases and tradeoff drills. Scoped, testable, and graded by a real judge.
Coming SoonFrontend 30 DaysSoon
A guided daily challenge track for sharper frontend reps. One problem a day for thirty days.
Coming Soon