Add migrations prerequisites

vb-migration/migration-prerequisites.md

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+# Enhanced Migration Prerequisites and Best Practices
+
+## Critical Prerequisites Before Migration
+
+### 1. Test Coverage Requirements
+- Implement comprehensive unit tests with minimum 80% code coverage
+- Create integration tests for all critical business workflows
+- Establish end-to-end tests for main user journeys
+- Document all test scenarios and expected outcomes
+- Set up automated test runs in CI/CD pipeline
+- Create performance benchmarks for critical operations
+- Implement API contract tests if applicable
+- Set up regression test suites
+
+### 2. Code Quality Baseline
+- Run static code analysis tools and fix all critical/high issues
+- Document and justify any suppressions of warnings
+- Remove all deprecated API usage
+- Clean up unused references and dependencies
+- Ensure consistent code formatting
+- Remove dead code and unused variables
+- Document all known technical debt
+- Fix all compiler warnings
+
+### 3. Documentation Requirements
+- Create detailed API documentation
+- Document all business rules and domain logic
+- Map out all external system integrations
+- Document configuration settings and their purposes
+- Create system architecture diagrams
+- Document all custom implementations and workarounds
+- Maintain a glossary of business terms
+- Document all scheduled tasks and batch processes
+
+### 4. Infrastructure and Environment
+- Set up separate environments for migration testing
+- Create rollback procedures
+- Implement monitoring and logging
+- Set up feature flags for gradual migration
+- Create backup and restore procedures
+- Document deployment procedures
+- Set up parallel run capabilities
+- Establish performance monitoring baselines
+
+### 5. Business Validation
+- Identify subject matter experts for each module
+- Create business validation test cases
+- Document critical business periods to avoid
+- Create business continuity plan during migration
+- Establish acceptance criteria for migration success
+- Document regulatory compliance requirements
+- Create data validation procedures
+- Establish UAT test plans
+
+## Enhanced Best Practices
+
+### 1. Code Organization
+- Implement clean architecture principles
+- Separate business logic from infrastructure code
+- Use dependency injection consistently
+- Implement repository pattern for data access
+- Use SOLID principles
+- Implement proper exception handling
+- Use consistent logging patterns
+- Implement proper configuration management
+
+### 2. Testing Strategy
+- Create smoke test suite for quick validation
+- Implement automated UI tests for critical paths
+- Create load and stress tests
+- Implement security testing procedures
+- Create data-driven tests for complex scenarios
+- Implement boundary testing
+- Create mutation tests for critical components
+- Establish performance testing benchmarks
+
+### 3. Version Control
+- Create feature branches for migration
+- Implement proper PR review process
+- Set up branch protection rules
+- Create meaningful commit messages
+- Document branching strategy
+- Implement version tagging
+- Create release notes template
+- Set up automated builds for all branches
+
+### 4. Migration Process
+- Start with smallest, least dependent modules
+- Create detailed checklist for each module
+- Implement feature toggles for gradual rollout
+- Create validation scripts for each phase
+- Document all migration decisions
+- Create progress tracking system
+- Establish regular checkpoints
+- Create contingency plans
+
+### 5. Post-Migration Validation
+- Create comparison tools for old vs new system
+- Implement parallel run procedures
+- Create data reconciliation processes
+- Document performance comparison metrics
+- Establish monitoring for regression issues
+- Create user feedback collection process
+- Implement automated health checks
+- Create system stability metrics
+
+### 6. Security Considerations
+- Perform security audit before migration
+- Document all security requirements
+- Implement security testing procedures
+- Create security validation checklist
+- Document authentication/authorization changes
+- Implement secure configuration management
+- Create security incident response plan
+- Perform penetration testing
+
+### 7. Performance Requirements
+- Establish performance benchmarks
+- Create performance test suites
+- Document scalability requirements
+- Implement performance monitoring
+- Create capacity planning documentation
+- Establish SLA requirements
+- Create performance optimization plan
+- Document resource utilization metrics
+
+### 8. Documentation Standards
+- Use consistent documentation format
+- Create documentation review process
+- Implement version control for documentation
+- Create API documentation standards
+- Establish documentation update procedures
+- Create user guides and training materials
+- Document troubleshooting procedures
+- Maintain decision log
+
+## Risk Mitigation Strategies
+
+### 1. Technical Risks
+- Create technical risk register
+- Implement mitigation strategies for each risk
+- Create fallback procedures
+- Document known limitations
+- Create technical debt register
+- Establish bug triage process
+- Create incident response procedures
+- Document system dependencies
+
+### 2. Business Risks
+- Document business impact analysis
+- Create business continuity procedures
+- Establish communication plans
+- Create stakeholder management plan
+- Document compliance requirements
+- Create data governance procedures
+- Establish change management process
+- Create training plans
+
+### 3. Operational Risks
+- Create operational procedures
+- Document support processes
+- Establish escalation procedures
+- Create monitoring procedures
+- Document backup procedures
+- Create disaster recovery plans
+- Establish SLA monitoring
+- Create capacity management plans