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    legacy-system-archaeologist

    legacy-system-archaeologist

    by J. Trejo

    Reconstruct architecture and map risks in inherited legacy codebases with evidence-based auditing and migration plans.

    Updated May 2026
    0 installs

    Free

    One-time purchase

    ⚡ Also available via Agensi MCP — your AI agent can load this skill on demand via MCP. Learn more →

    Included in download

    • Downloadable skill package
    • 2 permissions declared
    • Instant install

    See it in action

    System Health: CRITICAL
Risk Register:
- /app/services/billing_engine.rb: BLACK (High fan-in: 42, Git churn: high, 0 tests)
- /lib/legacy_utils.js: RED (Dead code candidate, but dynamic dispatch possible)
Plan: Implement 5 characterization tests on billing_engine before refactoring.

    Screenshots

    About This Skill

    What it does

    The Legacy System Archaeologist is a specialized toolkit for developers who have inherited "black box" codebases. It performs deep structural analysis to reconstruct system architecture, map dependencies, and identify high-risk modules before you write a single line of code.

    Why use this skill

    Modernizing legacy systems is dangerous because the "why" and "how" are often lost to time. While a standard AI might give you generic refactoring advice, this skill uses a rigorous 6-phase protocol—Inventory, Dependency Mapping, Risk Scoring, Dead Code Analysis, Architecture Reconstruction, and Strategy Reporting—to provide evidence-based insights.

    It goes beyond simple prompting by using dedicated scripts to calculate "fan-in" (coupling), git churn (instability), and risk classifications. You get a professional-grade audit that identifies "Black Zone" files (like auth or payments) that no agent or human should touch without characterization tests.

    Supported tools

    • Languages: Multi-framework support (Rails, Laravel, Django, Node, Spring, .NET)
    • Analysis Scripts: Python-based dependency graphers and risk scorers
    • Context: Git history analysis and static code analysis

    The Result

    You receive a structured documentation suite including an Executive Summary for stakeholders, a full System Map, a file-level Risk Register, and a phased Migration Plan based on the Strangler Fig pattern.

    📖 Learn more: Best Code Review Skills for Claude Code →

    Use Cases

    • Audit inherited codebases to identify high-risk "god objects" and coupling.
    • Generate a Strangler Fig migration plan for monolith decomposition.
    • Identify likely dead code candidates based on static analysis and git churn.
    • Create a System Map for onboarding new engineers to undocumented projects.
    • Flag "AI Danger Zones" where agents should not perform automated refactoring.

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    Security Scanned

    Passed automated security review

    Permissions

    Terminal / Shell
    Environment Variables

    Tags

    legacy-code
    architecture
    migration
    refactoring
    static-analysis

    Creator

    J. Trejo

    Frequently Asked Questions

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