$ practice --track sql,python,pandas

Sharpen the code you actually write as a data scientist.

Hand-written problems with a real editor. Your SQL runs against a live database, your Python runs a real interpreter — no setup, no notebooks, instant feedback.

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Free to start — Pro unlocks the full problem set across every track.

SQL

Joins, aggregation, CTEs and window functions run against a real SQLite database in your browser.

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Python

Lists, loops, sets, dicts, functions and generators — graded with hidden unit tests.

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Pandas

Filtering, groupby, merges, pivots and reshaping on real DataFrames, powered by Pyodide.

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