Arena Mode
Pick a sprint, draw relevant missions, and train accuracy under time pressure. The production model stores runs, scores, and arena ladder entries.
Arena modes
Timed practice with scoring, speed bonuses, and no-hint rewards.
10 minutessql
10-minute SQL Sprint
A fast read-only query gauntlet built for analysts and backend engineers.
Read-only SQL only
Deterministic ordering earns a bonus
No destructive statements
Mission draw
Find duplicate checkout transactions
Easy SQL arena: GROUP BY, HAVING, tie-safe ordering, and read-only analysis
Stabilize duplicate transaction detector
Medium SQL arena: GROUP BY, HAVING, tie-safe ordering, and read-only analysis
Warm up with retention cohort matrix
Easy SQL arena: date bucketing, joins, and cohort aggregation
Stabilize retention cohort matrix
Medium SQL arena: date bucketing, joins, and cohort aggregation
Warm up with window ranking leaderboard
Easy SQL arena: RANK, ROW_NUMBER, partitions, and deterministic tie breakers