Case Study: HCLTech modernizes COBOL to Java with CAST and AI

HCLTech boosts COBOL-to-Java accuracy 90%+ with CAST

HCLTech, a global technology company, faced mounting pressure to modernize large, interdependent COBOL estates for clients, contending with high costs, scarce talent, and the risk of failure in traditional multi-year programs. AI promised speed but struggled with accuracy on complex systems. To address this, HCLTech partnered with CAST and leveraged CAST Imaging's deterministic analysis.

By embedding CAST Imaging's context into its iLIT-AI platform via an MCP server, CAST provided a system-wide map that grounded the AI. In a pilot on a nine-million-line application, this combined solution extracted functional specifications and generated idiomatic Java. The results included an overall accuracy uplift exceeding 90%, up to 23% more efficiency in the rewrite, and the identification of up to 25% dead code for removal.

HCLTech