The nesting part is where things get interesting and also where I spent too long overthinking the data structure.
Start by clarifying requirements and scope, then propose a data model that supports nesting and toggling, and discuss trade-offs between different representations. Walk through the core operations (add, toggle, delete) with attention to efficiency and edge cases, and finally outline how you would test and scale the solution.
Pro tip: Demonstrate product thinking by connecting technical decisions to user experience—e.g., how toggling a parent affects children, and how to handle undo/redo—since Notion values seamless collaboration and block-based editing.
Ask questions to understand expected scale, persistence, real-time collaboration, and whether nesting depth is limited. Confirm if toggling a parent should cascade to children or be independent.
Propose a tree structure (e.g., nodes with parent/child references) and discuss alternatives like adjacency lists or nested sets. Explain how to represent done/undone state and handle ordering.
Detail how to add, toggle, and delete items, including recursive traversal for cascading toggles. Analyze time/space complexity and discuss optimizations like lazy loading or memoization.
Compare in-memory vs. persistent storage, and discuss handling of deep nesting, concurrent edits, and cycle prevention. Mention how to support undo/redo and versioning.
Describe unit tests for core logic and integration tests for UI interactions. Discuss how the design scales with large lists and potential optimizations like virtualization.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.