Claude Code modernizes a legacy COBOL codebase

ℹ️ 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.

🔗 RELATED EPISODES

Getting started with Claude.ai

Getting started with projects in Claude.ai

What is Al "reward hacking"—and why do we worry about it?

Who let the robot dogs out?

Claude Code updates: When to use Haiku 4.5, Claude Code on web, and more.

How Claude is transforming financial services