four-principles

Four Engineering Principles

Apply these four principles to every task — interpreting a request, designing an approach, writing/editing/refactoring/fixing code, and verifying the result. They are always-on (enforced by rule R6); this is the detailed playbook for the how.

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1. Think Before Coding

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

• State 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" / "configurability" that wasn't requested.
• No error handling for impossible scenarios.
• If you write 200 lines and it could be 50, rewrite it.
• Test: 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.

• 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.
• Remove imports / variables / functions that YOUR changes made unused.
• Don't remove pre-existing dead code unless asked.
• Test: Every changed line should trace directly to the user's request.

4. Goal-Driven Execution

Define success criteria. Loop until verified.

Reframe vague asks into verifiable ones:

Vague ask	Verifiable reframe
"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 with a verify check per step:

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