How do you compute multiple aggregation levels at once (GROUPING SETS, ROLLUP, CUBE)?
Reporting frequently needs subtotals and grand totals across several dimensions, and stitching that together with many UNIONs wastes work. The signal is GROUPING SETS, ROLLUP, and CUBE in one pass.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
Reporting frequently needs subtotals and grand totals across several dimensions, and stitching that together with many UNIONs wastes work. The signal is GROUPING SETS, ROLLUP, and CUBE in one pass.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
