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Figma Document Buffer
Also known as: Text Buffer with Undo/Redo
Implement a text buffer with insert/delete plus undo/redo. The core trap is that undoing deletes/replaces requires remembering exactly what text was removed.
Learn this pattern
Low-Level Design Interview Questions
Low-level design problems test whether you can model a small API, preserve invariants, and choose storage that matches the required operations. Expect recurring shapes like rate limiters, hit counters, tic-tac-toe, file systems, and autocomplete.
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