SQL is quietly becoming must-have bedrock. It’s the industry estimates #1 skill1 for data analysts in 2025, used by ~54%1 daily and powering 70%2 of advanced analytics.
AI can write queries, but it can’t clean messy data, spot weird churn signals, or explain why it matters—without you. GroupBySQL is a friendly dojo to practice those real moments.
AI amplifies whatever you feed it. Better SQL → cleaner inputs → faster, clearer decisions.
Every business question starts with a data fight. We train you to win both.
Messy logs. Broken joins. You fix it — and learn to trust your data.
NULLs, gaps, 10+ event types. You build the curve — and find the “why.”
47 lines of SQL → 3-line Slack: “Fix EMEA onboarding.” You learn to ship clarity.
What each challenge includes