---
name: principle-subtract-before-you-add
description: "Apply when new work would otherwise build on dead or redundant structure."
license: MIT
metadata:
  author: jstack-maintainers
  source: michael-denyer/pstack-claude
  source-version: "0.9.30"
  source-commit: 45f768349a6d7d7e71509fee3f5bccfad54b3bad
  owner: software-factory
  risk: low
  capabilities: jstack,engineering-principle
user-invocable: false
---

# Subtract Before You Add

When evolving a system, remove complexity first, then build.

**Why:** Adding to a complex system compounds complexity. Removing first leaves less code, reveals the essential structure, and usually makes the next design obvious. Default to subtraction.

Make simplification a continual investment. Leave the design slightly simpler and more capable behind the same or smaller surface than you found it.

**The pattern:**
- Sequence removal before construction
- Cut before you polish (get to the minimum before investing in quality)
- Design for observed usage, not speculative edge cases
- No speculative validators, parsers, or guards beyond what the spec demands
- Simplify prompts (remove redundant instructions, excessive templates)
- When a reference has no novel content, delete it rather than leaving a stub