Projects
Start with a beginner project and work up. Each one runs in your browser, with checks that tell you when it works.
These lessons are not a second catalog or a video course, and this tab cannot publish a repo for you. Passing every LakeBench lesson means you can write the transforms, the DAG habits, the tests, and the design argument. It does not publish a repo. The Cloud capstone is a numbered GCP free-tier checklist this tab cannot execute. Do those steps outside, then copy the solutions you wrote, add a README that states grain, schedule, and failure modes, and push that.
Incremental Spark MERGE, a simulated night job, dbt-shaped staging and tests, and a publish suite.
SQL & Warehousing
SQLBuild an enterprise cohort analysis query in SQL tracking customer return rates and churn across monthly acquisition cohorts.
CV: “Engineered an enterprise customer cohort retention matrix in SQL using CTEs, date truncation, and conditional aggregation in DuckDB.”
SQL & Warehousing
SQLTransform unstructured web clickstream event logs into discrete user sessions using LAG() window functions and cumulative sums.
CV: “Implemented enterprise web event sessionization in SQL utilizing LAG() window functions, EPOCH time math, and cumulative window aggregations in DuckDB.”
SQL & Warehousing
SQLQuantify customer conversion rates and stage drop-offs across a 4-step e-commerce funnel using conditional aggregation and chronological ordering.
CV: “Engineered a chronological e-commerce conversion funnel in SQL using conditional aggregation, timestamp progression filters, and stage drop-off math in DuckDB.”
SQL & Warehousing
SQLCalculate cumulative year-to-date net revenue and rolling 3-day moving averages in SQL using window frame specifications.
CV: “Built a financial treasury ledger in SQL computing running totals and 3-day moving averages using explicit window frame clauses in DuckDB.”
SQL & Warehousing
SQLRank and isolate top-performing catalog items within each retail category in SQL using DENSE_RANK() and CTE filtering.
CV: “Built an inventory replenishment ranking model in SQL using DENSE_RANK(), CTE window filtering, and revenue share math in DuckDB.”
SQL & Warehousing
SQLEliminate duplicate webhook events and resolve status conflicts deterministically using ROW_NUMBER() in SQL.
CV: “Built an idempotent webhook deduplication pipeline in SQL using ROW_NUMBER() window functions and multi-attribute tie-breaking in DuckDB.”
Late messages on a fake topic, a GCP free-tier deploy checklist, and the ship runbook order.
SQL & Warehousing
SQLReconstruct immutable temporal audit timelines with valid_from, valid_to, and current flags using LEAD() in SQL.
CV: “Engineered an immutable Slowly Changing Dimension Type 2 history pipeline in SQL using LEAD() window functions and sentinel expiration dates in DuckDB.”
SQL & Warehousing
SQLDetect consecutive daily user workout streaks and breaks using the classic SQL gaps-and-islands difference technique.
CV: “Implemented the classic SQL gaps-and-islands algorithm to detect consecutive daily activity streaks and breaks in DuckDB.”
SQL & Warehousing
SQLTraverse multi-level management reporting hierarchies and calculate organizational depth using recursive CTEs in SQL.
CV: “Engineered a recursive organizational hierarchy model in SQL using WITH RECURSIVE, dynamic depth calculation, and lineage path generation in DuckDB.”
SQL & Warehousing
SQLDiagnose execution plan bottlenecks, eliminate unindexed full table scans, and optimize warehouse query performance using predicate pushdown. The tuning principles were documented as internal engineering guidelines, preventing similar performance regressions across future analytics jobs. Adopting predicate pushdown as an engineering standard guaranteed consistent sub-minute processing times. Eliminating late filtering restored predictability to data warehouse operations and protected the enterprise from costly regulatory compliance penalties.
CV: “Optimized enterprise warehouse query performance using physical plan analysis, predicate pushdown, and columnar projection in DuckDB.”
Bigger projects you build over a few weeks on your own laptop. Each one comes with a week plan, starter code, viva questions with model answers and a resume line, so you can present it with confidence.
Intermediate · 5 weeks
Turn a raw sales file into a star schema and a dashboard a manager can read.
Open the planBeginner friendly · 4 weeks
Pull data from a public API every day, load it safely, and chart it.
Open the planBeginner friendly · 3 weeks
Clean messy student records and show placement rates by branch, skill and company.
Open the planBeginner friendly · 3 weeks
Check every new file against rules and send a clear pass or fail report.
Open the planIntermediate · 4 weeks
Spot unusual payments with SQL window functions and show them on a simple report.
Open the planIntermediate · 5 weeks
Turn a stream of page-view events into sessions, funnels and a daily report.
Open the planSame grain fights, in the studio.
The 12 to 18 month path that sequences these is on the roadmap.
