SQLwak is a free SQL learning game — no signup, no download. You're a Graduate Analyst at Lion City Bank (fictional Singapore bank) solving 57 real business SQL problems.
Foundational → Intermediate (JOINs) → Advanced (CTEs) → Expert (window functions like RANK OVER PARTITION BY).
9-table schema: retail banking + a maritime trade finance division with vessels and cargo shipments across SE Asia.
Built with Next.js 15 + SQLite via WebAssembly. All queries run client-side. Open source on GitHub.