What problem does it solve? Planning a legacy system migration without a structured, evidence-based approach leads to missed dependencies, broken integrations, and failed cutovers. This Skill produces comprehensive migration plans grounded in actual codebase analysis and verified external research, covering monolith decomposition, microservices consolidation, cross-language rewrites, and framework upgrades. ## Core Features & Use Cases - Two-Phase Methodology: A mandatory RESEARCH phase (codebase analysis, domain mapping, stack research, risk assessment) followed by a PLAN phase (seam design, per-domain migration files, consolidated roadmap). - Strangler Fig Pattern Library: Six proven patterns including API Gateway Strangler, Database Dual-Write, UI Component Strangler, and Branch by Abstraction, with phased traffic rollout and rollback triggers. - Testing Safety Nets: Characterization tests, contract tests, parallel runs, and data consistency validation mapped to each migration phase. - Use Case: You need to decompose a Node.js monolith into microservices. The Skill analyzes your codebase with file:line citations, identifies bounded contexts with coupling scores, researches current stack versions via web search, and outputs a phased roadmap with per-domain migration plans, rollback strategies, and risk mitigations. ## Quick Start Ask the agent to analyze this codebase and produce a legacy migration plan using the Strangler Fig pattern, starting with the research phase.
