Claude Code modernizes a legacy COBOL codebase

Watch how Claude Code helps modernize a mainframe codebase. Starting with code from an AWS Mainframe Modernization demo environment, Claude Code analyzes business logic, dependencies, and data flows, then helps refactor it into Java while preserving functionality. Claude Code handles the complex, multi-step work—generating documentation, developing migration plans, writing test suites, and iteratively validating the new code—directly from your terminal.

Nov 14, 20254mWatch on YouTube ↗

EPISODE INFO

Released: November 14, 2025
Duration: 4m
Channel: Anthropic
Watch on YouTube: ▶ Open ↗

EPISODE DESCRIPTION

Watch how Claude Code helps modernize a mainframe codebase. Starting with code from an AWS Mainframe Modernization demo environment, Claude Code analyzes business logic, dependencies, and data flows, then helps refactor it into Java while preserving functionality. Claude Code handles the complex, multi-step work—generating documentation, developing migration plans, writing test suites, and iteratively validating the new code—directly from your terminal.

EPISODE SUMMARY

In this episode of Anthropic, Claude Code modernizes a legacy COBOL codebase explores using Claude Code to document and migrate legacy COBOL safely The demo uses an AWS Mainframe Modernization sample repo (credit card system) to show how Claude Code can generate comprehensive documentation for an undocumented COBOL/JCL codebase.

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