Replacing 12K LoC with a 200 LoC Skill
summary
Claim: Cursor replaces a heavy WorkTrees feature with 200 lines of Markdown by re-implementing behavior using skills and subagents, exposing /worktree, /bestof and apply/delete commands. The repo-level result is roughly 15,000 lines deleted. Demonstrates isolation, multi-repo PRs, and best-of-N judging but exposes failure modes: models can forget worktree scope, feel slower, and hurt discoverability; mitigations are evals and RL training plans.
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chapters (12)
- 0:00Start
- 0:14Introduction and the concept of markdown as code
- 0:59Recap of Git work trees in Cursor
- 3:10Complexity of the initial implementation
- 4:18Deleting 15,000 lines of code
- 4:54Implementing features with Skills and Sub-agents
- 5:51How the new Skills are structured
- 7:58New Slash commands and workflow
- 9:58Pros of the new implementation
- 12:15Cons and user feedback challenges
- 14:17Future improvements: Evals and RL training
- 17:05What's next for Cursor 3.0 and native work trees
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