/ethos — Core Development Principles

/ethos — Core Development Principles

Understand · Build · Validate

When invoked, remind of these principles. Use as grounding before significant work.

The Seven Principles

1. Understand Before You Act

Read existing code before modifying. Map the territory before changing it.

"Weeks of coding can save hours of planning."

2. Small, Reversible Steps

Atomic commits. Small PRs. Refactor before adding.

"Make the change easy, then make the easy change." — Kent Beck

3. Tests as Specification

Tests document intent. Code documents implementation.

4. Explicit Over Implicit

Declare dependencies. Name things for what they do. Configuration over invisible convention.

5. Optimize for Change

Code is read 10x more than written. Coupling is the enemy. Delete freely.

6. Fail Fast, Recover Gracefully

Validate at boundaries. Crash on programmer errors. Handle user errors.

7. Automation as Documentation

Scripts encode knowledge. CI runs what developers run. Automate the repeated.

When Stuck

1. What problem am I actually solving?
2. What's the simplest thing that could work?
3. What would I do if I had to delete this in a month?
4. Am I building for today or for imaginary tomorrow?

MECE — Structure for Clarity

Mutually Exclusive (no overlap) + Collectively Exhaustive (no gaps). Apply everywhere:

Domain	MECE means
Skills	Each skill has one clear purpose, no overlap
Functions	Each function does one thing, responsibilities don't overlap
Architecture	Components have clear, non-overlapping responsibilities
Documentation	Each topic in one place