Migrating RPG Code to Modern Languages

Your RPG System Is a Ticking Clock. This Book Helps You Defuse It.

For decades, your RPG system has been the reliable heart of your business. But now, it's a liability. You can't find skilled developers, every change is slow and risky, and the platform is becoming a trap. You know you need to migrate, but the process feels intimidating, complex, and full of risk.

Stop waiting for a crisis. Migrating RPG Code to Modern Languages is the definitive, practical playbook for modernizing your IBM i applications before it's too late. This isn't just a technical manual; it's a strategic guide grounded in real-world experience that will give you the clarity and confidence to lead a successful migration.

What You'll Learn

This book gives you a complete roadmap, from initial planning to final deployment. You'll uncover how to:

• Build a Bulletproof Business Case: Understand the real reasons to migrate—from the scarcity of RPG skills to hardware costs—and get every stakeholder aligned on your "why" before you begin.
• Plan a Low-Risk Migration: Master the three phases of a successful migration: Planning, Migration, and Testing. Learn how to choose the right target language (Java, Python, or C#) and framework for your specific needs.
• Master the Technical Challenges: Get expert, proven strategies for translating the trickiest parts of your legacy system:
  • Tame GOTO statements by identifying common patterns and converting them into structured, modern control flow.
  • Translate cryptic RPG indicators into clear, maintainable code using local variables, exceptions, or domain types.
  • Modernize "green screen" UIs with a faithful reproduction or a complete redesign, separating UI logic from business rules.
  • Preserve your orchestration logic by translating essential CL scripts into clean, maintainable Python.
  • Handle the database migration, including when and why you should strategically keep DB2 to de-risk the project.
• Avoid Common, Costly Pitfalls: Learn from the hard-won lessons of past projects. Understand why you shouldn't wait for the last RPG developer to retire and why overlooking the human side of migration is a recipe for failure.
• Implement a Professional-Grade Testing Strategy: Build a suite of equivalence tests using Gherkin to prove the new system behaves exactly like the old one, transforming a project cost into a long-term asset.
• See a Real Migration Pipeline in Action: Get a behind-the-scenes look at the Strumenta Migration Pipeline, a robust infrastructure for parsing, analyzing, and transforming millions of lines of code accurately and traceably.

Who Is This Book For?

This playbook is for everyone with a stake in a legacy modernization project:

• CTOs and IT Directors who need to build the strategic case for migration.
• Software Architects responsible for designing the new system's architecture.
• Project Managers tasked with planning and executing the migration with confidence.
• RPG Developers who hold deep knowledge of the existing system and are vital to its successful evolution.
• Modern Developers (Java, Python, C#) who will inherit, maintain, and extend the migrated codebase.