--- name: framework-migration-legacy-modernize-1e386a9e2ea3 description: "Orchestrate a comprehensive legacy system modernization using the strangler fig pattern, enabling gradual replacement of outdated components while maintaining continuous business operations through ex" risk: unknown source: community date_added: "2026-02-27" --- # Legacy Code Modernization Workflow Orchestrate a comprehensive legacy system modernization using the strangler fig pattern, enabling gradual replacement of outdated components while maintaining continuous business operations through expert agent coordination. [Extended thinking: The strangler fig pattern, named after the tropical fig tree that gradually envelops and replaces its host, represents the gold standard for risk-managed legacy modernization. This workflow implements a systematic approach where new functionality gradually replaces legacy components, allowing both systems to coexist during transition. By orchestrating specialized agents for assessment, testing, security, and implementation, we ensure each migration phase is validated before proceeding, minimizing disruption while maximizing modernization velocity.] ## Use this skill when - Working on legacy code modernization workflow tasks or workflows - Needing guidance, best practices, or checklists for legacy code modernization workflow ## Do not use this skill when - The task is unrelated to legacy code modernization workflow - You need a different domain or tool outside this scope ## Instructions - Clarify goals, constraints, and required inputs. - Apply relevant best practices and validate outcomes. - Provide actionable steps and verification. - If detailed examples are required, open `resources/implementation-playbook.md`. ## Phase 1: Legacy Assessment and Risk Analysis ### 1. Comprehensive Legacy System Analysis - Use Task tool with subagent_type="legacy-modernizer" - Prompt: "Analyze the legacy codebase at $ARGUMENTS. Document technical debt inventory including: outdated dependencies, deprecated APIs, security vulnerabilities, performance bottlenecks, and architectural anti-patterns. Generate a modernization readiness report with component complexity scores (1-10), dependency mapping, and database coupling analysis. Identify quick wins vs complex refactoring targets." - Expected output: Detailed assessment report with risk matrix and modernization priorities ### 2. Dependency and Integration Mapping - Use Task tool with subagent_type="architect-review" - Prompt: "Based on the legacy assessment report, create a comprehensive dependency graph showing: internal module dependencies, external service integrations, shared database schemas, and cross-system data flows. Identify integration points that will require facade patterns or adapter layers during migration. Highlight circular dependencies and tight coupling that need resolution." - Context from previous: Legacy assessment report, component complexity scores - Expected output: Visual dependency map and integration point catalog ### 3. Business Impact and Risk Assessment - Use Task tool with subagent_type="business-analytics::business-analyst" - Prompt: "Evaluate business impact of modernizing each component identified. Create risk assessment matrix considering: business criticality (revenue impact), user traffic patterns, data sensitivity, regulatory requirements, and fallback complexity. Prioritize components using a weighted scoring system: (Business Value × 0.4) + (Technical Risk × 0.3) + (Quick Win Potential × 0.3). Define rollback strategies for each component." - Context from previous: Component inventory, dependency mapping - Expected output: Prioritized migration roadmap with risk mitigation strategies ## Phase 2: Test Coverage Establishment ### 1. Legacy Code Test Coverage Analysis - Use Task tool with subagent_type="unit-testing::test-automator" - Prompt: "Analyze existing test coverage for legacy components at $ARGUMENTS. Use coverage tools to identify untested code paths, missing integration tests, and absent end-to-end scenarios. For components with <40% coverage, generate characterization tests that capture current behavior without modifying functionality. Create test harness for safe refactoring." - Expected output: Test coverage report and characterization test suite ### 2. Contract Testing Implementation - Use Task tool with subagent_type="unit-testing::test-automator" - Prompt: "Implement contract tests for all integration points identified in dependency mapping. Create consumer-driven contracts for APIs, message queue interactions, and database schemas. Set up contract verification in CI/CD pipeline. Generate performance baselines for response times and throughput to validate modernized components maintain SLAs." - Context from previous: Integration point catalog, existing test coverage - Expected output: Contract test suite with performance baselines ### 3. Test Data Management Strategy - Use Task tool with subagent_type="data-engineering::data-engineer" - Prompt: "Design test data management strategy for parallel system operation. Create data generation scripts for edge cases, implement data masking for sensitive information, and establish test database refresh procedures. Set up monitoring for data consistency between legacy and modernized components during migration." - Context from previous: Database schemas, test requirements - Expected output: Test data pipeline and consistency monitoring ## Phase 3: Incremental Migration Implementation ### 1. Strangler Fig Infrastructure Setup - Use Task tool with subagent_type="backend-development::backend-architect" - Prompt: "Implement strangler fig infrastructure with API gateway for traffic routing. Configure feature flags for gradual rollout using environment variables or feature management service. Set up proxy layer with request routing rules based on: URL patterns, headers, or user segments. Implement circuit breakers and fallback mechanisms for resilience. Create observability dashboard for dual-system monitoring." - Expected output: API gateway configuration, feature flag system, monitoring dashboard ### 2. Component Modernization - First Wave - Use Task tool with subagent_type="python-development::python-pro" or "golang-pro" (based on target stack) - Prompt: "Modernize first-wave components (quick wins identified in assessment). For each component: extract business logic from legacy code, implement using modern patterns (dependency injection, SOLID principles), ensure backward compatibility through adapter patterns, maintain data consistency with event sourcing or dual writes. Follow 12-factor app principles. Components to modernize: [list from prioritized roadmap]" - Context from previous: Characterization tests, contract tests, infrastructure setup - Expected output: Modernized components with adapters ### 3. Security Hardening - Use Task tool with subagent_type="security-scanning::security-auditor" - Prompt: "Audit modernized components for security vulnerabilities. Implement security improvements including: OAuth 2.0/JWT authentication, role-based access control, input validation and sanitization, SQL injection prevention, XSS protection, and secrets management. Verify OWASP top 10 compliance. Configure security headers and implement rate limiting." - Context from previous: Modernized component code - Expected output: Security audit report and hardened components ## Phase 4: Performance Validation and Optimization ### 1. Performance Testing and Optimization - Use Task tool with subagent_type="application-performance::performance-engineer" - Prompt: "Conduct performance testing comparing legacy vs modernized components. Run load tests simulating production traffic patterns, measure response times, throughput, and resource utilization. Identify performance regressions and optimize: database queries with indexing, caching strategies (Redis/Memcached), connection pooling, and async processing where applicable. Validate against SLA requirements." - Context from previous: Performance baselines, modernized components - Expected output: Performance test results and optimization recommendations ### 2. Progressive Rollout and Monitoring - Use Task tool with subagent_type="deployment-strategies::deployment-engineer" - Prompt: "Implement progressive rollout strategy using feature flags. Start with 5% traffic to modernized components, monitor error rates, latency, and business metrics. Define automatic rollback triggers: error rate >1%, latency >2x baseline, or business metric degradation. Create runbook for traffic shifting: 5% → 25% → 50% → 100% with 24-hour observation periods." - Context from previous: Feature flag configuration, monitoring dashboard - Expected output: Rollout plan with automated safeguards ## Phase 5: Migration Completion and Documentation ### 1. Legacy Component Decommissioning - Use Task tool with subagent_type="legacy-modernizer" - Prompt: "Plan safe decommissioning of replaced legacy components. Verify no remaining dependencies through traffic analysis (minimum 30 days at 0% traffic). Archive legacy code with documentation of original functionality. Update CI/CD pipelines to remove legacy builds. Clean up unused database tables and remove deprecated API endpoints. Document any retained legacy components with sunset timeline." - Context from previous: Traffic routing data, modernization status - Expected output: Decommissioning checklist and timeline ### 2. Documentation and Knowledge Transfer - Use Task tool with subagent_type="documentation-generation::docs-architect" - Prompt: "Create comprehensive modernization documentation including: architectural diagrams (before/after), API documentation with migration guides, runbooks for dual-system operation, troubleshooting guides for common issues, and lessons learned report. Generate developer onboarding guide for modernized system. Document technical decisions and trade-offs made during migration." - Context from previous: All migration artifacts and decisions - Expected output: Complete modernization documentation package ## Configuration Options - **--parallel-systems**: Keep both systems running indefinitely (for gradual migration) - **--big-bang**: Full cutover after validation (higher risk, faster completion) - **--by-feature**: Migrate complete features rather than technical components - **--database-first**: Prioritize database modernization before application layer - **--api-first**: Modernize API layer while maintaining legacy backend ## Success Criteria - All high-priority components modernized with >80% test coverage - Zero unplanned downtime during migration - Performance metrics maintained or improved (P95 latency within 110% of baseline) - Security vulnerabilities reduced by >90% - Technical debt score improved by >60% - Successful operation for 30 days post-migration without rollbacks - Complete documentation enabling new developer onboarding in <1 week Target: $ARGUMENTS --- ## AGI Framework Integration > **Adapted for [@techwavedev/agi-agent-kit](https://www.npmjs.com/package/@techwavedev/agi-agent-kit)** > Original source: [antigravity-awesome-skills](https://github.com/sickn33/antigravity-awesome-skills) ### Memory-First Protocol Retrieve prior error resolutions and debugging strategies. The hybrid search excels here — BM25 finds exact error codes/stack traces while vectors find semantically similar past issues. ```bash # Check for prior debugging/diagnostics context before starting python3 execution/memory_manager.py auto --query "error patterns and debugging solutions for Framework Migration Legacy Modernize" ``` ### Storing Results After completing work, store debugging/diagnostics decisions for future sessions: ```bash python3 execution/memory_manager.py store \ --content "Root cause: memory leak from unclosed DB connections in pool — fixed with context manager" \ --type error --project \ --tags framework-migration-legacy-modernize debugging ``` ### Multi-Agent Collaboration Store error resolutions so any agent encountering the same issue retrieves the fix instantly instead of re-debugging. ```bash python3 execution/cross_agent_context.py store \ --agent "" \ --action "Debugged and resolved critical issue — root cause documented for future reference" \ --project ``` ### Self-Annealing Loop When this skill resolves an error, store the fix in memory AND update the relevant directive. The system gets stronger with each resolved issue. ### BM25 Exact Match Error codes, stack traces, and log messages are best found via BM25 keyword search. The hybrid system automatically uses exact matching for these patterns. --- Source attribution: techwavedev Original project: https://github.com/techwavedev/agi-agent-kit/blob/58f5d95434a1adc8b41a4f391d32d95311e54936/templates/skills/extended/debugging/framework-migration-legacy-modernize/SKILL.md License: Apache-2.0 License information: https://www.apache.org/licenses/LICENSE-2.0 Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. "Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity. "You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License. "Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files. "Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types. "Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below). "Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof. "Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to the Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution." "Contributor" shall mean Licensor and any individual or Legal Entity on behalf of whom a Contribution has been received by Licensor and subsequently incorporated within the Work. 2. Grant of Copyright License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form. 3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed. 4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions: (a) You must give any other recipients of the Work or Derivative Works a copy of this License; and (b) You must cause any modified files to carry prominent notices stating that You changed the files; and (c) You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License. You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License. 5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions. 6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file. 7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License. 8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages. 9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability. END OF TERMS AND CONDITIONS APPENDIX: How to apply the Apache License to your work. To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives. Copyright 2024-2026 Elton Machado (TechWaveDev) Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. # Mega AI Hub resource metadata Creator / publisher: techwavedev Original project: https://github.com/techwavedev/agi-agent-kit/blob/58f5d95434a1adc8b41a4f391d32d95311e54936/templates/skills/extended/debugging/framework-migration-legacy-modernize/SKILL.md Attribution basis: Source repository record Fields of work: Development & Engineering, Operations, Product Management Roles: Backend Developer, Business Process Analyst, DevOps / SRE, Product Manager, Technical Product Manager Specialties: API, Backend, Database, Design, DevOps, Word Documents, Excel, Frontend, Git, Mobile, Playwright, Testing Tools: Task Tool Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: 382249290a32f745ac0ef681fa16c0e9753c1d3e789dd97c941d3d55c54dc4d2