Unravelling the past, rebuilding the future, with Bob

APIS IT, a Croatian public ICT provider supporting government digital services, needed to modernize a broad set of mission‑critical systems that had accumulated decades of technical debt. Several foundational workloads, including early‑1990s JCL/PL/I (Job Control Language/Programming Language One) jobs, Java 8 applications, and a 20‑year‑old EGL (Enterprise Generation Language) system running on IBM CICS (Customer Information Control System), had little to no documentation and depended heavily on institutional knowledge. This made it difficult to understand current‑state architectures and slowed efforts to plan modernization safely. Meanwhile, the testing team required a comprehensive automation solution capable of orchestrating REST (Representational State Transfer) APIs, SOAP (Simple Object Access Protocol) services, and database interactions—capabilities that would traditionally take weeks or months to build from scratch.

Further modernization needs surfaced within APIS IT’s .NET estate, where a decade‑old SOAP service required migration to a modern REST architecture, and an internal .NET Core 3.1 API Manager had accumulated unnecessary dependencies and technical debt. Updating these systems manually would demand significant engineering effort and introduce risk across platforms.

To progress, APIS IT needed a solution capable of rapidly interpreting legacy systems, accelerating documentation, and supporting modernization at scale across both mainframe and modern applications.

As part of its broader transformation program, APIS IT began early testing of IBM® Bob, IBM’s SDLC partner. Bob’s hybrid, open, and extensible architecture allowed it to integrate directly into APIS IT’s existing environment, enabling rapid analysis of both legacy and modern systems with minimal setup.

APIS IT first applied Bob to its most complex mainframe and legacy workloads. Using coordinated execution and automated validation, Bob analyzed more than 36 JCL jobs and a multi‑module PL/I application, reverse‑engineering execution flows and dependencies while generating comprehensive technical documentation and Mermaid architecture diagrams. Bob also interpreted a 20‑year‑old EGL/CICS application, producing complete multi‑format documentation and Python tooling for diagram conversion to deliver architectural clarity that previously required extensive manual effort.

In the .NET ecosystem, Bob delivered similar acceleration. Using multi‑step planning and iterative refinement, Bob refactored a 10‑year‑old SOAP service into a modern .NET 8 REST API within hours, preserving existing business logic while generating production‑ready code with zero compilation errors. Bob also modernized APIS IT’s internal .NET Core 3.1 API Manager by removing unnecessary database dependencies, simplifying over‑engineered patterns, migrating configuration to application files, and upgrading the solution to .NET 8. Throughout the process, Bob’s shell and remote‑shell capabilities enabled dependency cleanup, build validation, and detailed before‑and‑after architecture documentation.

IBM Bob delivered rapid, material gains across some of the organization’s most complex modernization priorities. Bob enabled teams to interpret legacy workloads that had gone undocumented for decades, producing complete Croatian‑language documentation for JCL/PL/I jobs with 100% operator‑verified accuracy. This clarity unlocked safe advancement of modernization efforts that had long depended on institutional knowledge. Bob also brought transparency to a deeply aged EGL/CICS system, generating multi‑format architecture documentation and process analysis 10× faster than manual methods, giving APIS IT actionable insight into one of its most mission‑critical platforms.

To support testing, Bob enabled the delivery of a complete React + SQLite test automation platform in just two days, representing a 5–6× productivity gain over traditional LLM‑assisted approaches. The resulting solution provided APIS IT with a modular, production‑ready foundation for automated testing across REST, SOAP, and database workflows.

Within the .NET estate, Bob further compressed modernization timelines. A decade‑old SOAP service was fully refactored into a modern REST API within hours, with 100% of the code updated and zero compilation issues. Bob also simplified an internal API Manager by removing unnecessary dependencies, streamlining architectural patterns, migrating configurations, and upgrading the solution to .NET 8—work that would typically require weeks, completed in five to six hours. These refinements reduced the codebase by 30%, eliminated 50% of dependencies, and improved performance and memory efficiency.

Bob helped APIS IT break through long‑standing barriers and drive faster progress across its legacy and modern systems. With consistent accuracy, speed, and architectural insight, Bob enabled APIS IT to move from discovery to delivery with confidence—achieving results in hours instead of weeks.

APIS IT is Croatia’s leading public ICT provider and a key technology partner to the Croatian government. With over 60 years of experience, it delivers secure, high-quality IT services that support the digital transformation of public administration and modernize government business processes.