qMentor

qMentor is the fast way to get fluent in q and kdb+ — the array language behind the world's highest-performance time-series databases, used across quant finance and beyond. Instead of passively reading docs, you practice. Every question shows a real snippet of q, asks you to predict the output, then explains exactly why — so right-to-left evaluation, the overloaded glyphs, and the qSQL quirks finally click. WHAT'S INSIDE • 800 hand-written questions across 16 units and 52 lessons • Fundamentals first — atoms, lists, dictionaries, tables • Then qSQL, functional queries, iterators, and amend/apply • Real-world depth: market-data idioms (VWAP, OHLC, asof joins), tick architecture (TP/RDB/HDB), performance tuning, the .z and .Q namespaces, overloaded operators, and system commands • A dedicated Interview Prep unit for kdb+/q job questions • PyKX and the wider KX ecosystem HOW IT WORKS • Each session draws 5 questions at random from a large bank, so replaying a lesson gives fresh questions every time • Read the code, choose the output, learn from the explanation • Earn XP and build a daily streak to keep the habit going • Every lesson is unlocked — jump straight to what you want to drill BUILT FOR FOCUS • Clean, dark, terminal-style interface • Works fully offline • No account, no ads, no tracking — your progress stays on your device Whether you're prepping for a kdb+ interview, ramping up at a new desk, or just curious about the language that makes q developers so productive, qMentor turns spare minutes into real fluency. qMentor is an independent educational app and is not affiliated with, endorsed by, or sponsored by KX Systems, Inc. "kdb+", "q", and "KX" are trademarks of their respective owners.