using-software-engineering

# Software Engineering Foundations

Universal methodology for professional software engineering practice. Language-agnostic foundations that apply regardless of tech stack.

## Core Principle

**Engineering excellence is methodology, not heroics.** Systematic approaches beat clever improvisation. These skills encode battle-tested processes for situations where "just figure it out" leads to wasted time and missed root causes.

## When to Use

Load this skill when:
- Facing a bug that resists simple fixes
- Need to refactor safely without breaking things
- Reviewing code (yours or others')
- Production is on fire
- Deciding what technical debt to address
- Taking ownership of code you don't fully understand

**Don't use for**: Language-specific issues (use language packs), algorithm design (use CS fundamentals), infrastructure/deployment (use DevOps packs).

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## How to Access Reference Sheets

**IMPORTANT**: All reference sheets are in the SAME DIRECTORY as this SKILL.md.

When this skill is loaded from:
  `skills/using-software-engineering/SKILL.md`

Reference sheets like `complex-debugging.md` are at:
  `skills/using-software-engineering/complex-debugging.md`

NOT at:
  `skills/complex-debugging.md` (WRONG PATH)

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## Routing by Situation

### Horrible Bugs

**Symptoms**:
- Bug resists simple fixes
- "I've tried everything"
- Intermittent failures
- Works on my machine
- Can't reproduce reliably
- Multi-system interactions
- Heisenbugs (changes when observed)
- Race conditions suspected

**Route to**: [complex-debugging.md](complex-debugging.md)

**Why**: Systematic debugging methodology using scientific method. Adapted for Claude's strengths (fast codebase reading, pattern recognition) and limitations (no interactive debuggers).

**Integration**: For domain-specific bugs, use this methodology THEN hand off to specialists:
- PyTorch issues → `yzmir-pytorch-engineering` (debug-oom, debug-nan)
- RL training → `yzmir-deep-rl` (rl-debugging)
- Simulation chaos →