karpathy-guidelines

---

name: karpathy-guidelines description: Use when writing, reviewing, or refactoring code in this repo to reduce common LLM coding mistakes — overcomplication, drive-by edits to unrelated lines, hidden assumptions, vague success criteria. Four principles: Think Before Coding, Simplicity First, Surgical Changes, Goal-Driven Execution. license: MIT source: https://github.com/forrestchang/andrej-karpathy-skills

Karpathy Guidelines

Behavioral guidelines to reduce common LLM coding mistakes, derived from Andrej Karpathy's observations on LLM coding pitfalls. Adapted from forrestchang/andrej-karpathy-skills (MIT).

Tradeoff: These guidelines bias toward caution over speed. For trivial tasks (typo fix, obvious one-liner), 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.

Working in This Repo

This project is verification documentation + LLM-DNA experiments — most "code" is markdown, YAML, or short Python scripts. The principles still apply:

• Think Before Coding: When the user reports an unexpected result (e.g., the Solar/Mixtral identical-DNA issue), surface the diagnosis and tradeoffs (re-extract vs. exclude vs. switch dataset) before acting.
• Simplicity First: For one-shot scripts in experiments/llm-dna/scripts/, prefer 50 readable lines over 200 lines of "configurable" abstraction.
• Surgical Changes: Don't reformat or rewrite wiki/ pages while editing one; don't restructure tutorial files while adding one Q&A.
• Goal-Driven Execution: SageMaker spot jobs need explicit success criteria up-front (e.g., "DNA extraction produces non-empty signature of length 128 with non-trivial variance"); don't claim success on Status=Completed alone.

Working / Not Working

Working	Not working
Diff contains only what the user asked for	Drive-by reformatting in unrelated files
Clarifying question came before edits	Discovered wrong assumption after the work landed
50-line script that solves the task	200-line script with unused configuration knobs
Verifiable success criteria stated up front	"Make it work" with no defined check