Compare short-term and long-term moving averages for the S&P 500 to identify "golden cross" moments – signifying the start of a bull market. Ideal for practicing rolling calculations and conditional flags.

Match each order in a table with the promotion active on its date, if applicable. Ideal for practicing non-traditional joins based on date ranges or intervals.

Build reporting hierarchies, count direct and total reports, and map employee-manager relationships using organizational data. Ideal for practicing recursive logic and data modeling skills.

Identify the users with the longest daily active streaks based on their lessons completed. Ideal for practicing date comparisons, lag functions, and streak logic.

Analyze monthly sales and track performance trends in this hands-on data drill. Group transactions by store and month, then calculate month-over-month changes to uncover key insights.

Summarize the viewing activity for each Netflix user. Ideal for practicing logic-based feature engineering and aggregation.

Flatten a nested JSON column into individual rows in this intermediate data drill. Transform order records with embedded line items into a flat table format, then calculate total online sales. Ideal for practicing data transformation and aggregation skills.