27 questions · 27 match your filters
| Status | Title | Technology | Topic | Acceptance | Difficulty |
|---|---|---|---|---|---|
| ○ | 12.Fix a slow groupBy on 2B rows | PySpark | Spark optimization | — | Hard |
| ○ | 13.Second highest salary per department | SQL | Window functions | 100.0% | Easy |
| ○ | 14.Month-over-month revenue growth | SQL | Window functions | — | Medium |
| ○ | 16.Running balance per account | SQL | Window functions | — | Medium |
| ○ | 18.Gaps and islands in device uptime | SQL | Window functions | — | Hard |
| ○ | 19.Cohort retention by signup month | SQL | Data modeling | — | Hard |
| ○ | 20.Latest price as of each order | SQL | Data modeling | — | Medium |
| ○ | 21.Validate JSON records against a schema | Python | Data modeling | — | Easy |
| ○ | 22.Merge overlapping time ranges | Python | Aggregation | — | Medium |
| ○ | 23.Chunked aggregation over a large CSV | Python | Aggregation | — | Medium |
| ○ | 24.Retry with exponential backoff | Python | Data modeling | — | Medium |
| ○ | 25.Parse fixed-width log lines | Python | Data modeling | — | Easy |