Hey everyone! Long time.
I haven't posted anything here since my last post on November 21st last year. Life has been a bit busy, balancing work and home, especially with the delightful chaos my 2-year-old twin boys bring into the picture. 🙂
Over the last five months, I’ve constantly thought about writing my next blog post. I even created rough drafts on several topics, but somehow never found the time to complete them.
Last month, I visited the Chennai Pen Show and bought an acrylic fountain pen from Click Pens.
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| The Acrylic Fountain Pen that I bought from Click Pens. The model name is Renaissance. |
I came to a realization when I went back home and began writing with it. I already had a number of great fountain pens in my stationery drawer and bag, but I wasn't using them enough.
So, I decided to change something.
Instead of typing the blog drafts directly on my laptop, I'll be writing them on my notebook using my fountain pens.
And here is my first blog post following the new trend.
Recently, I had the opportunity to write a COBOL DB2 program from scratch. As a Mainframe developer, this isn’t unusual. But the tools and the way I approached development this time were completely different.
About 99% of the code was written on VS Code using IBM Z Open Editor and Zowe Explorer.
Alongside the development process, I conversed with GitHub Copilot (mostly using Claude Opus 4.5 & 4.6 models) to better design the structure and flow of the program.
It was a great experience compared to the traditional way of coding. You always have the AI assistant at your service, helping you structure logic, name your paragraphs, write loops, and handle repetitive tasks. You provide clear context, and the AI does a lot of the heavy lifting.
However, one thing became very clear to me:
AI is powerful, but not perfect without human oversight. Human involvement is still essential for effective collaboration.
For instance, when the initial cut of development was complete, I asked the AI assistant to perform a robust and comprehensive peer review. It highlighted several issues, which I fixed. Confident with the changes, I began staging the program in Endevor. To my surprise, the staging still failed due to several issues.
One of them was related to MOVE statements.
In my initial version, I had the MOVE statements like the following:
MOVE GROUP-A.VAR-1 TO GROUP-B.VAR-1.
However, during compilation, these MOVE statements were flagged as errors.
What’s worth noting is that the initial version of these MOVE statements was suggested by the AI assistant. Although it captured the intent correctly, it overlooked COBOL-specific syntax requirements, which eventually caused compilation failures.
To fix this, I had to replace all such occurrences of the MOVE statement with dot notation to OF notation like below:
MOVE VAR-1 OF GROUP-A TO VAR-1 OF GROUP-B.
There were plenty of such occurrences that I instructed the AI assistant to replace all the MOVE statements with proper notation.Based on my overall experience, I found that Claude models did a fairly better job when it came to generating COBOL code, especially when clear context was provided.
For instance, I had a requirement to perform a credit limit check for all customers within a group. The logic was simple in intent but required careful structuring. The program should proceed to the next step only if all customers in the group pass the check. If even one customer fails, the entire group should be skipped, and processing should continue with the next group.
When I described this to the model, it suggested an “all-or-nothing” approach and generated the corresponding COBOL logic. What stood out was that the solution was not just syntactically correct but also logically aligned with the requirement, and it worked as expected with minimal changes.
This experience showed me that AI is particularly effective when the problem is clearly defined.
That’s all for now. I’ll be back soon with another blog post and possibly a new series: “AI in My Daily Mainframe Life.”
As a closing thought, I recently added a cool little piece to my work desk, a 3D-printed z17 model that also doubles as a pen stand.
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| 3D Printed z17 model Pen Stand |
For the curious folks, I used the 3D design files that I found here
Would love to hear what you think. Let me know in the comments.
Thanks for reading!