Todo list system design in codeCodingDesign and implement a small todo list system with lists, tasks and completion state. Reported on 1point3acres' Notion bank; reconstructed in our own words.
Last asked Jun 2026
Notion practical coding and debugging interview
Round 4 of 7 · 11 questions reported
- Length
- 60 min
- Format
- Coding or debugging inside a realistic codebase
- They grade
- Readable code and a debugging process: reproduce, hypothesize, instrument, verify
Questions Notion asks in this round 11
- Top K error strings in a time windowCodingGiven request-response log entries with timestamps, report the K most frequent errors inside a sliding time window. Reported on 1point3acres' Notion bank; reconstructed in our own…Last asked Jun 2026
- DAG utility with add, validate and queryCodingBuild a small directed-acyclic-graph helper: add edges, reject ones that would create a cycle, and answer reachability or ordering queries over the graph. Reported on…Last asked Apr 2026
- Block type with the most childrenCodingOver a tree of typed document blocks, find which block type has the most children in total. Reported on 1point3acres' Notion bank; reconstructed in our own words.
- Country with the most eventsCodingGroup product events by country and return the country with the most events. Reported on 1point3acres' Notion bank; reconstructed in our own words.
- Event type with the most eventsCodingCount product events by type and return the type with the highest count. Reported on 1point3acres' Notion bank; reconstructed in our own words.
- Most popular plan type for the top event typeCodingOver product event data, find the most common event type, then the most popular plan type among users producing it. Reported on 1point3acres' Notion bank; reconstructed in our own…
- Nested todo list with subtasksCodingModel a todo list whose items can nest subtasks to any depth: add, complete and list tasks while keeping the hierarchy. Reported on 1point3acres' Notion bank; reconstructed in our…
- Page permission managementCodingImplement page-level permissions: grant and revoke access for users on pages, and answer whether a user can view or edit a page, respecting the page hierarchy. Reported on…
- Percentage of blocks never editedCodingFrom block edit events, compute what share of blocks was never edited after creation. Reported on 1point3acres' Notion bank; reconstructed in our own words.
- SQL screening with joins and window functionsCodingA SQL screen covering joins, aggregation and window functions over product data. Reported on 1point3acres' Notion bank; reconstructed in our own words.