Most modernization projects fail the same way: they start rebuilding before they understand what they're rebuilding. I see this constantly. A new CTO joins, looks at 40-year-old COBOL code, and declares "we're getting off the mainframe." The next thing you know, they've hired a team of Java developers to rewrite everything for the cloud. Three years and several million dollars later, they're still not done. The new system performs worse than the old one. Critical features got missed. And they end up having to hire back the COBOL developers they let go—at much higher salaries.

Frank Chu, Senior Software Engineer at ColeSoft, was recently elected to join the board of SHARE, an independent volunteer-run information technology association that provides education, professional networking and industry influence for the enterprise IT community. Frank shares his thoughts about his new role - and the role of SHARE in the mainframe community.

Debugging mainframe applications requires flexibility in how you initiate your debugging environment. Z/XDC provides five distinct methods to start debugging sessions, each tailored to different scenarios and workflows. Let's walk through all five options and help you figure out which approach fits your specific situation best.

AI-generated code promises to revolutionize development: write a prompt, get working code, ship faster. The reality looks different. AI produces code that compiles, runs, and does something. Whether it does what you actually need is another question entirely.

Watching code execute instruction by instruction changes how mainframe developers approach debugging and modernization. For teams working with legacy systems, this kind of visibility makes a real difference.

Mainframe teams often find themselves trapped in a cycle of defensive testing, building elaborate test suites that take longer to maintain than the code they're meant to protect. When you can't see what your code actually does during execution, the natural response is to test everything, just in case.

Finding bugs: Overlooking the Obvious. How many times have you read your code and overlooked the obvious? It's probably happened a lot because there are a number of common cognitive biases that lead even the best developers to miss bugs in their own code, even after multiple personal reviews. Why do these blind spots occur, how does mental fatigue and familiarity impact debugging, and - most importantly - how can programmers develop practical techniques to improve error detection? 

I have added disassembly support for all new opcodes and extended mnemonics as documented in the recently published -14 edition of z/Architecture Principles of Operation.

Frank Chu of Izzi Software Elected to SHARE Board as Director at Large. Leading information technology association selects IT specialist to promote education, networking, and leadership for global enterprise computing ecosystem

Debugging on the mainframe can be a daunting task, often leading developers to resort to time-consuming and risky workarounds. While sometimes necessary, some workarounds can significantly impact delivery timelines and affect team morale. Before turning to solutions like ColeSoft’s Z/XDC, developers often find themselves stuck in a cycle of inefficiency and frustration.