Bob for IBM Z: Bringing Agentic AI to COBOL & the Mainframe with Rich Larin

Why it matters

At IBM TechXchange, RedMonk analyst Kate Holterhoff interviewed Rich Larin, Director of Z DevX & Platform Engineering at IBM, about applying AI tooling to mainframe work. Larin framed the problem clearly: mainframes still process credit card transactions and airline reservations, but the applications running on them, largely written in COBOL, PL1, and assembler, have existed for decades and are difficult to maintain or extend. IBM's answer is Bob and the Premium Package for Z, which bring an agentic IDE to mainframe developers so that COBOL can be handled like any other language, such as Java or Node. Larin emphasized that customers genuinely value COBOL for high-throughput workloads; the gap has been modern tooling. He also described deployment flexibility, including SaaS, hybrid, and air-gapped on-premises options for customers protecting source code, plus a deterministic security scan that Bob can remediate automatically. The interview, sponsored by IBM, positions mainframe modernization as an AI-driven effort to break down the platform's traditional isolation and attract newer developers.