Reimagining mainframe applications with AWS Transform and Claude Code

This article explains how to modernize mainframe applications by combining AWS Transform for reverse engineering with Claude Code for forward engineering cloud-native microservices.

• AWS Transform extracts business rules, data lineage, and domain structure from COBOL/PL/I codebases
• Claude Code generates modern microservices, targeting Java, Python, .NET, and other technology stacks
• Three-phase workflow: reverse-engineer legacy system, generate specifications with human validation, then code generation with testing
• CLAUDE.md provides persistent project context; Skills package repeatable workflows as slash commands
• Spec generation applies Business Rule Extraction and Domain-Driven Design methodologies
• Code generation produces database schemas, microservices, unit tests, and infrastructure-as-code
• Human-in-the-loop validation required before code generation to ensure specification accuracy

The Reimagine approach preserves critical business logic while rearchitecting legacy applications as scalable, maintainable cloud-native services.