Quarry: SQL & Python Prep

Hand-picked SQL, pandas & Python interview problems that run entirely on your device. Auto-graded, with hints and solutions. No account, no internet.

Quarry is a focused, offline gym for data and coding interviews. 108 hand-picked problems across SQL, pandas, and Python — write real code, run it on your device, and get graded instantly.

Everything runs on-device. The SQL and Python engines are built into the app, so there's no sign-up, no internet requirement, and nothing you write ever leaves your phone or iPad. Practice on a plane, on the subway, or anywhere.

WHAT'S INSIDE • 108 problems across three tracks: SQL queries, pandas data wrangling, and Python algorithms & data structures. • Real execution, real grading. Your output is checked against the expected result — no self-marking. • Company tags. Filter problems by the company you're interviewing at. • Hints and full solutions when you're stuck. • Difficulty levels from Easy to Hard, grouped by topic. • A free-form Playground for scratch SQL and Python. • Universal app — designed for both iPhone and iPad.

PRIVATE BY DESIGN No accounts. No analytics. No ads. No tracking. Quarry collects nothing and works fully offline.

Whether you're prepping for a data analyst, data engineer, data scientist, or software role, Quarry gives you a quiet, fast place to actually practice.