THE CHALLENGE
Legacy systems remain a significant burden for financial institutions. While reliable, they bring serious risks — from shrinking pools of skilled operators and operational bottlenecks, to mounting pressure to modernise and meet new regulations. Existing COBOL-to-Java tools often produce unreadable "Jobol" code, making explanation-focused tools far more valuable than direct conversion.
THE SOLUTION
Critical Software developed an AI generative chatbot designed to analyse and explain legacy codebases, giving development teams the foundation they need to modernise confidently. The solution enables institutions to:
Analyse legacy programmes and explain their functionality and business logic
Generate pseudo-code for rewriting in modern languages such as Python or Java
Understand data models and how legacy applications interact with databases
Create code-flow diagrams to support modernisation
Get real-time answers to questions about the legacy codebase
THE TECHNOLOGY
The solution is built on large language models (LLMs) and retrieval-augmented generation (RAG), delivered through an interactive AI interface on a cloud-first architecture with private LLM support.
Early results from the chatbot demonstrate its ability to accelerate modernisation while maintaining accuracy and reducing costs:
400+ lines of COBOL translated into Java in under a week
80% first-attempt test pass rate across 300 test cases, significantly reducing debugging overhead
Faster time-to-market, deeper preservation of business logic, notable cost savings, and improved client satisfaction