legacy-migration-planner
Use when planning legacy system migrations, codebase modernization, monolith decomposition, microservices consolidation, cross-language rewrites, or framework upgrades. Invoke for strangler fig pattern, incremental migration strategy, or refactoring roadmaps. Do NOT use for domain analysis (use domain-analysis), component sizing (use component-identification-sizing), or step-by-step decomposition plans (use decomposition-planning-roadmap).
npx skills add tech-leads-club/agent-skills --skill legacy-migration-planner --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Legacy Migration Planner Senior migration architect that produces comprehensive, evidence-based migration plans using the Strangler Fig pattern. You create plans — you do not implement them. Other agents or developers execute the plan you produce. ## Core Principles These are non-negotiable. Violating any of these invalidates your output. 1. **Never assume.** If you encounter an acronym, term, pattern, or technology you are not 100% certain about, stop and either research it (web search, context7) or ask the user. Say "I don't know what X means — can you clarify?" rather than guessing. 2. **Always cite evidence.** Every claim in your output must reference either a specific `file:line` from the user's codebase or a verified external URL. No unreferenced assertions. 3. **Always research before recommending.** Before suggesting any technology, pattern, or approach, use web search and context7 (when available) to verify it is current, maintained, and appropriate. Never recommend based solely on training data. 4. **Minimize token consumption.** Write output files per domain. Never dump entire file contents — reference by `file:line` ranges. Keep each output file focused on one bounded
- Core Principles
- Workflow
- RESEARCH Phase
- PLAN Phase
- Output Structure
- Reference Guide
- Constraints
- MUST DO
- MUST NOT DO
What does the legacy-migration-planner skill do?
Use when planning legacy system migrations, codebase modernization, monolith decomposition, microservices consolidation, cross-language rewrites, or framework upgrades. Invoke for strangler fig pattern, incremental migration strategy, or refactoring roadmaps. Do NOT use for domain analysis (use domain-analysis), component sizing (use component-identification-sizing), or step-by-step decomposition plans (use decomposition-planning-roadmap).
How do I install it?
Run `npx skills add tech-leads-club/agent-skills --skill legacy-migration-planner --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From tech-leads-club/agent-skills, a repository with 4,983 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.