Real broken code. Real interview pressure. An AI coach that refuses to just hand you the answer. Practice the part of interviews that actually tests your thinking.
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Three stages. No hand-holding between them.
Select from multiple real interview formats across Easy, Medium, and Hard. Each is a broken implementation waiting to be fixed.
A live test runner shows what's failing. An AI coach in the sidebar answers questions but won't write the fix for you.
Six behavioral axes, an AI-generated headline about your session, and a full timeline of every decision you made.
Not LeetCode. Not flashcards. Actual interview simulation.
Pre-broken implementations from actual interview patterns. Find and fix the bugs, no blank-slate busywork.
Hints redirect your thinking toward the bug. The coach refuses to write the fix and notices when you rubber-stamp its suggestions.
Scored on Diagnosis, Independence, Precision, Verification, Recovery, and Test Ownership. Not just pass/fail.
EventEmitter (Meta), LRU Cache (Amazon), Prefix Trie (Google), Rate Limiter, Transaction Engine, and 6 more.
Adds realistic interviewer pressure: scope creep, over-engineering bait, correctness doubts. Practice staying focused.
Instant feedback on every edit. Hidden tests reveal edge cases once you complete each part.
Each one is a real broken implementation. A sample:
Three bugs: listeners fire in reverse order, off() wipes the whole event, once() never removes itself.
Sentinel nodes never linked, eviction hits the wrong end, and get/put skip MRU promotion entirely.
Drops the last field on every row, strips leading whitespace, and enters quote mode at the wrong character.
search() returns True for prefixes, get_words_with_prefix() builds results in reverse, case handling is inconsistent.
+ 7 more: Rate Limiter, Feature Flags, Log Query Filter, Dependency Resolver, Merge Intervals, and others.
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