karpathy-guidelines

Karpathy Guidelines

Behavioral guidelines to reduce common LLM coding mistakes, derived from Andrej Karpathy's observations on LLM coding pitfalls.

Tradeoff: These guidelines bias toward caution over speed. For trivial tasks, use judgment.

1. Think Before Coding

Don't assume. Don't hide confusion. Surface tradeoffs.

Before implementing:

• State your assumptions explicitly. If uncertain, ask.
• If multiple interpretations exist, present them - don't pick silently.
• If a simpler approach exists, say so. Push back when warranted.
• If something is unclear, stop. Name what's confusing. Ask.

2. Simplicity First

Minimum code that solves the problem. Nothing speculative.

• No features beyond what was asked.
• No abstractions for single-use code.
• No "flexibility" or "configurability" that wasn't requested.
• No error handling for impossible scenarios.
• If you write 200 lines and it could be 50, rewrite it.

Ask yourself: "Would a senior engineer say this is overcomplicated?" If yes, simplify.

3. Surgical Changes

Touch only what you must. Clean up only your own mess.

When editing existing code:

• Don't "improve" adjacent code, comments, or formatting.
• Don't refactor things that aren't broken.
• Match existing style, even if you'd do it differently.
• If you notice unrelated dead code, mention it - don't delete it.

When your changes create orphans:

• Remove imports/variables/functions that YOUR changes made unused.
• Don't remove pre-existing dead code unless asked.

The test: Every changed line should trace directly to the user's request.

4. Goal-Driven Execution

Define success criteria. Loop until verified.

Transform tasks into verifiable goals:

• "Add validation" → "Write tests for invalid inputs, then make them pass"
• "Fix the bug" → "Write a test that reproduces it, then make it pass"
• "Refactor X" → "Ensure tests pass before and after"

For multi-step tasks, state a brief plan:

1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]

Strong success criteria let you loop independently. Weak criteria ("make it work") require constant clarification.

---

Skill Relationships

Category

Code Quality & Review

Dependencies

None — standalone behavioral overlay. No file inputs or outputs.

Relationships

Skill	Pattern	Condition	Handoff Artifact
claude-code-director	Behavioral overlay	always-on during any implementation phase	— (modifies HOW coding runs, not what is produced)
plaid (Build phase)	Behavioral overlay	always-on when executing docs/product-roadmap.md tasks	—
code-review / ce-code-review	Domain cluster	sibling in the code quality domain; code-review assesses output, karpathy-guidelines governs process	—
simplify	Domain cluster	sibling; simplify cleans up after implementation, karpathy-guidelines prevents overcomplication during it	—

Runtime Preamble

This skill has no interactive invocation. It is an always-on overlay: whenever any implementation work runs in a project that has loaded karpathy-guidelines, these four rules govern how Claude codes — not as a checklist to recite, but as internalized behavior.

---

Gotchas

• This is a behavioral overlay, not a checklist: Do not recite these rules to the user before every edit. Internalize them and code accordingly. If a rule is being violated in the current task, name the violation once and correct course.
• "Simplicity first" does not mean "no error handling": It means no error handling for impossible scenarios. Errors that can realistically occur must still be handled.
• Surgical changes applies to edits, not new files: When writing a new file from scratch, write it cleanly. The surgical rule governs changes to existing code — don't touch what you weren't asked to touch.
• Goal-driven execution requires a stated plan for multi-step tasks: For single-line fixes, stating a plan is overkill. Apply judgment — require explicit verification steps only when multiple things could go wrong independently.
• Don't use this skill as a reason to slow down trivial tasks: The guidelines say "for trivial tasks, use judgment." Asking for clarification on a one-liner typo fix is overhead, not caution.