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SQL · Python · PySpark · Prompt eng · For Candidates · B2C
Practice Sandboxes
Run real code in your browser. No setup, no Docker, no cloud bill.
AI helps the recruiter; a human always decides.
Use case · when to reach for it
You want to practice the exact thing you'll do in a take-home, not watch a YouTube video about it.
What it does
DuckDB-WASM for SQL. Pyodide for Python (numpy + pandas). A pyspark-on-pandas shim so PySpark drills run client-side. A prompt-eval sandbox that calls Gemini. Curated questions across 11 kinds — every one of them runnable end-to-end in your browser.
DuckDB-WASM SQL
Window functions, recursive CTEs, qualify — all client-side.
Pyodide Python
numpy + pandas pre-loaded, no venv to manage.
PySpark shim
F.col / Window / broadcast — runs on pandas under the hood.
What's in the box
DuckDB-WASM SQL drills
Pyodide Python drills
PySpark-on-pandas drills
Gemini prompt eval
35+ curated questions
Daily challenge + leaderboard
Ready to see Practice Sandboxes in action?
Included in the platform — see the full pricing matrix to find your fit.