ask costa for data

The Data Analyst Roadmap.

A full course you actually do, not just watch. Real SQL and Python running in your browser, taught from production work — not sanitized curriculum.

Find your level ▸ Or browse the lessons
Start here
0 Find your level20 questions across 5 skills → your personalized roadmap › ▤ Learn hubEvery concept explained, with visuals and deep dives › ▶ Motion explainersWatch GROUP BY, HAVING, JOINs and windows actually happen ›
The modules
2 SQL 23 exercisesBasics → joins & aggregates → CTEs, CASE, window functions › 3 Python 23 exercisesFoundations → pandas → feature engineering › 4 Data CleaningTypes, missing values, duplicates, outliers › 5 Exploratory AnalysisDistributions, relationships, better questions › 6 StatisticsMean vs median, spread, correlation — with animations › 7 A/B TestingHypotheses, p-values, and the traps that fake a win › 8 VisualizationPick the chart, declutter it, make the title the takeaway › 9 Communicating InsightsThe one-sentence takeaway and the 4-beat story › 10 Leverage AI5 prompts, and when NOT to trust it › 11 Git & GitHubadd → commit → push, and the README that gets interviews ›
Boss level
★ The CapstoneReal messy data, a real question. Build it end to end. ›
Built in public by @ask.costafordata
Everything runs in your browser. No account, no setup.