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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.
Meet Allison & Tim
Your AI coaches
Practice coding interviews out loud with real-time voice coaching. Your code actually runs.
Desktop required to run this problem
StrongYes runs real code + tests in a desktop editor. Mobile is view-only for now, so you can’t start this here. Sorry about that — email yourself a link and pick it up on your computer.
Start Part 1 to unlock your next challenge
Desktop required
Sorry — mobile can’t run the editor + tests yet. Email yourself a link to continue on desktop.