In the fast-evolving world of enterprise technology, integrating modern solutions into legacy systems is both a necessity and a challenge. IBM mainframes, known for their reliability and high performance, remain central to many organisations. However, successfully incorporating technologies like Java requires expertise and vision. Leading this transformation, Chandra Mouli Yalamanchili has set new standards in modernising mainframe environments.

As a subject matter expert (SME) in Java on IBM mainframes, Yalamanchili has played a pivotal role in advancing modernisation efforts. “Modernising mainframes is not just about adding new technology; it's about ensuring stability and scalability,” he explains. Leading a team of 15 professionals, he has re-engineered over ten critical applications that integrate seamlessly with the company’s authorisation platform. His contributions earned him the prestigious Expert Engineer Award, recognising his innovative approach to bringing Java into mainframe systems.

The results of these efforts speak for themselves. By implementing modern interfaces, the organisation has retained major banking clients while attracting high-profile new ones, contributing to multi-million-dollar revenue growth. “Optimising vendor integration was key,” Yalamanchili notes. “We had to ensure real-time, high-volume transactions were handled efficiently while leveraging zIIP engines for cost-effectiveness.”

One of the most impactful developments under his leadership has been the creation of RESTful Java APIs in CICS Liberty. These APIs handle over 10 million client API calls daily, providing secure and scalable access to mainframe data. Additionally, the vendor orchestration layer he developed enables seamless processing of nearly 50 million vendor API calls per day, streamlining complex interdependencies.

Security has also been a top priority. “Encrypted socket communication between distributed systems and Java applications has been a game-changer,” Yalamanchili explains. This innovation has fortified real-time data exchanges, ensuring integrity and reducing risk. Standardising Java-based batch processing has further simplified modernisation efforts across teams, making the transition smoother for the entire organisation.

Despite these successes, the journey has not been without obstacles. One major challenge was the lack of established best practices for running complex Java applications within CICS-based Liberty JVMs. “We had to design solutions that maintained business functionality while introducing self-healing and monitoring mechanisms,” he says. Another hurdle was the 256 concurrent thread limitation per JVM, which required strategic application design to optimise performance.

Monitoring also presented difficulties, as traditional tools like Dynatrace did not fully support mainframe-based JVMs without high costs. Yalamanchili’s team addressed this by utilising native mainframe tools like SYSVIEW alongside custom logging mechanisms, ensuring proactive issue resolution. Recognising the skills gap in mainframe Java expertise, he developed comprehensive documentation and training resources, accelerating onboarding and fostering cross-functional collaboration.

His impact extends beyond his organisation. His research paper, Advanced Integration of Java EE Capabilities within CICS Liberty JVM Architecture, has guided modernisation efforts industry-wide. “Sharing knowledge is crucial,” he emphasises. “It ensures sustainable, long-term innovation.”

Looking ahead, Yalamanchili envisions Kubernetes playing a major role in orchestrating Java workloads on IBM mainframes, with real-time Java microservices complementing traditional batch processing. “Hybrid cloud-mainframe architectures are the future,” he asserts. “Bridging legacy and modern systems is not just about technology—it’s about driving business growth and long-term efficiency.”