system-layer-extractionlisted

# System Layer Extraction Investigate an entire codebase file-by-file to extract every system, map their boundaries, dependencies, state, lifecycle, and isolation potential. Produce a comprehensive layered architecture document and interactive visualization. This is slow, thorough work. The value comes from reading actual source code — not READMEs, not architecture docs, not summaries. Every file gets read. Every import gets traced. The output is a document that makes the invisible structure visible. --- ## Why This Matters Codebases accumulate structure over time that nobody fully sees. Systems intertwine. Dependencies form that aren't in any diagram. State gets shared in ways the original authors didn't intend. This skill makes all of that explicit — so you can refactor with confidence, onboard new contributors faster, and identify where isolation is strong vs where it's fragile. --- ## The Process ### Step 1: Set Up Create a working branch so the output files don't pollute the main branch: ```bash git checkout -b system-layer-extraction ``` ### Step 2: Map the Territory Before reading any code, get the full picture of what exists: ```bash # All non-test source files, sorted find src -name "*.ts" ! -name "*.test.ts" ! -name "*.spec.ts" | sort # All source directories find src -type d | sort # Line counts per directory (rough sizing) find src -name "*.ts" ! -name "*.test.ts" | xargs wc -l | sort -n ``` This gives you the raw material: how many files, how they