Join host Steven Dickens in this timely I Am a Mainframer episode featuring Geoffrey Decker, instructor at Northern Illinois University, who has spent more than 24 years preparing the next generation of mainframe professionals. As students head back to class, Geoffrey offers a real look at how assembler and COBOL can still open doors to meaningful, high-paying careers in today’s technology landscape.
Geoffrey shares how he teaches foundational mainframe skills to thousands of students, why assembler can feel intimidating at first, and how hands-on learning with ISPF, VS Code, IntelliJ, and Zowe helps students build confidence and capability. He also explains why his students are not just learning theory — they’re landing internships and jobs, including a recent graduate offered $115,000 to start as an assembler systems programmer trainee.
The conversation also explores the broader perception of mainframe education, the ongoing debate around curriculum changes, and why Geoffrey believes the so-called skills gap is really a question of how employers value emerging talent. With AI becoming part of the conversation, he shares a practical view of how it can help document and preserve legacy systems while still relying on skilled COBOL and assembler developers.
This back-to-school episode highlights the power of a proven university pipeline, the value of teaching timeless technical foundations, and the role education plays in strengthening the future of the mainframe ecosystem.
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Transcript:
Steven:
“Hello and welcome. You’ll join us here on another episode of the I Am a Mainframer Podcast, and I’m so glad to have Jeff Dickens from Northern Illinois University on the show. Hey Jeff!”
Geoffrey Decker:
“Hey! It’s so nice to be here, and I want to thank you for the privilege. I’m excited.”
Steven:
“What has it taken us seven years to make this a reality? I’ve got no idea.”
Geoffrey Decker:
“You do, man.”
Steven:
“Me neither, but it doesn’t matter. I’m just happy to be here today, and I really appreciate it. So I’ve known you for a long time, but maybe just position your role and what you do for the listeners and viewers, and then we can dive straight in.”
Geoffrey Decker:
“I am an instructor at Northern Illinois University in DeKalb, Illinois, and I teach mainframe at NIU. I teach a course in assembler, and I teach another course after that. I call it a smorgasbord of mainframe stuff, but I train students to get ready for the mainframe world, and I don’t give them anything that’s too modern because I feel strongly about giving them something that’s very basic and foundational for what they can do when they go on to their careers.”
Steven:
“So if I’m going to give you a long time, I’ll ask you the first question, probably a tough one to get us going. How many students do you think you’ve gone through your program over the years, and how many people have you taught basic mainframe skills to?”
Geoffrey Decker:
“I’ve been here 24 and a half years, and that whole time I’ve taught at least COBOL each semester. I would say probably somewhere in the 5,000-student range. Every semester I have between 100 and 150 mainframe students in my section and in the section that is taught by one other instructor in the department, an assembler.”
Steven:
“What are these kids? Is it kids in their freshman year? Is it their sophomores? Where are they typically when you get to them?”
Geoffrey Decker:
“Well, it’s kind of funny actually, because they avoid taking the assembler course. It’s a requirement of the Bachelor of Science degree at NIU, and I hope it continues to be that. But C++ is the major language that our students learn. They take three semesters of that. They take data structures in C++. They have the option to take Java and Python. But then they are required to take the beginning assembler course, and believe it or not, some take it in the junior year, some take it in the senior year, more take it in the senior year, in the fall of the senior year. They shouldn’t put it off that long because I think that they should kind of simmer in it for a while and then take the second class I offer too.”
Steven:
“So, tell me a little bit about what we’re talking to the 20-year-olds, 19-, 20-, 21-year-olds. Tell me more about their reaction when they get exposed to assembler for the first time. I imagine most of these kids are at one point wanting to be gaming developers.”
Geoffrey Decker:
“Of course. They want to be full stack developers. That’s their vision for themselves.”
Steven:
“So, lots of reaction when they get their hands on assembler and a 3270 screen for the first time.”
Geoffrey Decker:
“It’s, ‘Oh my God, what in the heck have I gotten myself into here?’ When you teach a class like assembler, you have to approach it very carefully. The word on the street amongst the students and their Discord that they all share is that, ‘Oh, you don’t want to take this course. You want to avoid it at all costs,’ but they can’t if they want their degree.”
Steven:
“So what is that message in Jeff? Why do people want to avoid it at all costs? What’s the hard part?”
Geoffrey Decker:
“It’s hard. I think it’s the most difficult course. “
Steven:
“Is that constantly inherent capabilities and structure of the language, or is it you’re just a tough grader?”
Geoffrey Decker:
“A little bit of both, actually. It’s so hieroglyphic, you know, that’s what I tell them. It’s so hieroglyphic and it’s so low level, and there’s nothing there to help you do it. So, you know, they have to start from the very beginning. I give them the JCL, I give them a program they can copy and paste into ISPF, and that’s where they start.”
Geoffrey Decker:
“It’s not that I keep them in ISPF. I actually let them go into using VS Code or IntelliJ and Zowe as soon as I feel that their ISPF has been learned well enough.”
Steven:
“So, first couple of weeks in, they’re like, what the hell is this? What’s the reaction sort of halfway through the course? Where are the kids kind of at and what do you see?”
Geoffrey Decker:
“You know, a surprising number of them as of late have heard others talk about the mainframe and talk about assembler from those students that have come to Share or TechXchange with me. And so, the word on the street is far more positive than it’s been over the last 20 years or so. So they really, really get into it. Most of them do, if they come to class and I require them to attend. If they come to class, I think maybe my level of enthusiasm for assembler and for the mainframe really gets them going. And then the other students, they see their success in getting internships and jobs. So you can’t argue with that.”
Steven:
“I think if your lecturer comes in infused and passionate, that rubs off on the students. So, you’ve roughly 5,000 kids come through. There’s got to be some standouts, some success stories. You’ve gone on to their careers in the mainframe space. You’ve probably got hundreds that you could mention, but is there two or three that stand out, Jeff, that would be great examples?”
Geoffrey Decker:
“Yeah, I don’t know if I should really mention their names, but I’ll go ahead and do it. There have been some exceptional ones. We had the Master the Mainframe winner, and I think it was 2015, maybe 2017. His name is Kevin Matezi. He works now for McMaster-Carr.”
Steven:
“It was impressive. If you have spoken to some of the Master the Mainframe winners over the years, they’re always super bright. You don’t win that competition by accident.”
Geoffrey Decker:
“Yeah, well, you know what? At the end of his third stage, I think he wrote his program in the third stage in assembler. And if he’s the one that I’m thinking about, he displayed something at the end of that third stage. Take that, Java.”
Steven:
“One of the big challenges that we hear is that there’s a skills gap. I know you’ve got a track record on the bona fide of training 5,000 students over a 20-year career to have access to the mainframe. When you hear the phrase, ‘there’s a mainframe skills gap,’ what’s your reaction? What do you say?”
Geoffrey Decker:
“I agree that there’s a skills gap, but there are students coming out of universities and training programs that are perfectly capable to step into a career. It’s only the employers that are causing the skills gap to be perpetuated. I feel that strongly.”
Steven:
“What are those students coming out of your program able to take in entry-level jobs that have got the right skills every year?”
Geoffrey Decker:
“Absolutely. And there are a lot of those positions that are advertised, maybe on LinkedIn or wherever, that want five years of experience. Well, I feel very confident that the students coming out of my second-level mainframe class have that five years already under their belt, or really close to it. So they can step into a job and become immediately productive for that organization.”
Steven:
“And when you see these, I mean you’ve probably got a huge enough sample size now. If you were to sort of do a comparative analysis of a kid who comes out and goes into a mainframe-based environment and a kid who goes out to be a Java developer or game developer, what are you seeing?”
Geoffrey Decker:
“Well, I don’t really keep track of it, and I really should. I’ve only recently started kind of asking students once they get their offers what they were offered, just so I can keep track of it. Here’s the thing: a student comes out of NIU with all of those full-stack development capabilities, Java, optional C++, optional Python. And if they take my two courses, well, they have to take the assembler. But if they take the second course that I teach, which I call the mainframe smorgasbord, they’re very valuable. They tend to be offered more, at least from what I’ve heard, than the other full-stack developers that plan to go into a Java position or web development position or something like that. I recently had a student hired, and he’s doing remote. He’s living near campus here with his parents. And he’s been offered $115,000 a year to start, and he’s going to be an assembler systems programmer trainee. And that’s really pretty darn good for somebody that can live with his parents and not have to move anywhere.”
Steven:
“Fantastic. And I say this to students all the time whenever I have the opportunity: if you’re going to pick one course, consider a COBOL and assembler mainframe course, which is yours.”
Steven:
“So, I mean, what’s the reaction amongst the wider faculty and community, all the professionals in NIU, toward the mainframe? Because I can imagine the platform’s got a perception. It sort of has certain things that, and a smell that goes around it from those who are less familiar with it. And you’re always pushing back on that challenge. How do you look to address that? Case in point: a kid coming straight out of college getting offered a $115K remote job. That’s a pretty strong argument. And the reaction you get from people like Master the Mainframe students within NIU, I can imagine how you defend it, but do you have to defend it? And then the second question is, if you do, how do you do that?”
Geoffrey Decker:
“Well, NIU’s Department of Computer Science is going to do a massive overhaul soon. I forget how many faculty members we have, but all of us voted whether to do a minor change to maybe move towards Python and other such changes. But also, I think in that overhaul will be the removal of assembler as a requirement for our undergraduate Bachelor of Science degree. And therefore, they’re going to remove it. Probably won’t even be an option, and then of course my upper-level course would be gone too. There’s been a push to get rid of the mainframe requirements and even the mainframe curriculum at NIU since about 2005, maybe before that, I’m sure. One good thing that came out of the pandemic was that the planned curriculum changes were pushed back. And so now we’ve got momentum and even a different idea about what it needs to be changed to.”
“And one of the things that a friend of mine posted, Dusty Rivers posted on LinkedIn, was, ‘NIU is getting rid of their mainframe,’ and he gave a list of all these people to contact by letter, not by email, but by letter at NIU to maybe try to change the situation or slow down the changes. Most — no disrespect to my colleagues in the department — but most of them have not worked in industry. And I have. I spent 11 years as a financial developer in Kansas City, Missouri, in the 1990s. And I know the value. And of course, talking to people at SHARE and TechXchange, I know the value of the mainframe. And there’s only so much of that I can foist on my colleagues. It’s hard to do, really.”
Steven:
“I mean, I’ve known you for probably 10 years at LEADS Net, Jeff. Our paths have crossed in various capacities, and you always do sterling work — not only to support the mainframe community, but also to support your students, the work you do by bringing them to SHARE and other conferences. You can chat to them on podcasts over the years. We’ve spoken to a whole bunch of them. I think that pipeline coming out of college is interesting to me at least, and then looking at the overall sector…”
Steven:
“I think, for me, if I could speak to your provost and some of your academic overlords, I’d be saying: here’s a proven program with over 5,000 students that have gone through it, some notable names, being offered $115K straight out of college. It’s something that doesn’t happen very often. You’ve obviously got a proven track record of taking kids through not only their academic years, but into those early years as a professional, which is just vital. I mean, as we look at the university equation in the US and the cost and dynamics of university, being able to say these kids went on to get really well, a six-figure-paying job straight out of college is a fantastic through line to prove the return on investment. And some people are questioning that return on investment. It’s not about chasing what’s new and cool on the shiny object. It’s about giving these kids a pathway into what’s going to be a well-paid job with good benefits that can help wider society. That’s my round over, Jeff, but I think there’s a lot to be said for that.”
Geoffrey Decker:
“Oh, I think a lot. And now that I think about it, there’ve got to be more than 5,000 students that have come through the program taking mainframe, if every graduate of the program has had to take assembler. So each one of those has probably come through my class in the last 20 years at least. But you know, there are three other universities in Illinois that recently started up their mainframe curriculum again. They’re using the IBM-provided materials, and they even contacted me asking if I would like to teach their assembler course because they have no one to teach it.”
Geoffrey Decker:
“Ass embler course remotely? But because of my union, and because I’m at NIU, I can’t do that. They wouldn’t allow it. But I’ll tell you what: when I retire, it may happen if I leave NIU. The journey is not over. The journey is going to continue a long time as long as I can. You’re going to have to pry that keyboard out of my cold, dead fingers, I guess you can say..”
Steven:
“I love it. I love it. So Jeff, as we start to sort of get towards the middle of the show, we’ve been chatting 15, 20 minutes already, and I can chat to you for hours. What I mean is, you’re at some of these mainframe conferences. We talked about SHARE. We talked about TechXchange. We’ve got to get you to GSE UK.”
Steven:
“What signals or trends are you seeing from the mainframe community, and what should we be watching for closely now? One of those big negative trends — you’re not a vendor, you’re not an enterprise that’s using the platform, so I’ve got to get your perspective as a passionate watcher of the community if you will.”
Geoffrey Decker:
“Well, I know there are a lot of people that I meet at SHARE and important people that I meet at SHARE who are always asking me why don’t I introduce this or introduce that in my curriculum. The problem with that, Steven, is that I don’t have time. I fit COBOL, the complete COBOL training in my second class, along with so many other things. That I don’t have time to bring in all of the cool stuff that’s going on. I don’t really have the time to bring AI into generative AI or anything into my coursework. Although I would love to. I respect it, and I believe it’s a critical trend of the future and end of the present. But I think we’ve got some students — you may have met them on campus — that created a product known as ZCraftor. And ZCraftor is a way to do not only assembler development with AI embedded in it, but to also do, I believe, other languages, anything on the mainframe.
Steven:
We must have been asked to probably consider donating that to the open source community and the Open Mainframe Project.
Geoffrey Decker:
They are working with Joe Winchester and they’ve got Zowe involved in it. I don’t know the product well enough, and I’m ashamed to say I don’t because the students are brilliant. They’ve been, you probably met them at SHARE, and I respect that very much.”
Geoffrey Decker:
“I respect AI. The thing I don’t like about AI is that people — and it’s not AI’s fault — is that people are saying that AI is going to rewrite COBOL or it’s going to replace something. My own thoughts on that, and they’re very uneducated, is that AI can be used to document existing systems and their context, things that were lost over the last 50, 60 years in systems that are still running COBOL programs from the 60s and the 70s. Documentation was done on paper back then and those paper logs are probably long gone or hard to read. AI can go in there and it can figure it out, and that’s the best thing I think can come out of AI. Here’s the thing: COBOL, we know — almost everybody knows this in the mainframe world — COBOL is an extremely easy language to learn. It’s got its quirks, but it’s easy to learn. Just teach these people COBOL, and you’re going to have COBOL people to verify that the generative software developed by AI is doing the same thing. So you’re going to have to have COBOL developers, that’s all there is to it, and assembler developers.”
Steven:
“I ask these two questions of everybody, so I’ll ask them to you. You get the opportunity to go back to a younger, darker-haired, more handsome if such a thing is possible, 22-year-old Jeff, coming out of college. What would you say to that?”
Geoffrey Decker:
“My undergraduate was in music, music history emphasis. And I worked at a stock stop for two years before a friend of a friend said, ‘You should try a master’s in computer science,’ because I really didn’t have the money to go to graduate school or learn to be a conductor like I really wanted to be. But fortunately I found a niche in computer science and programming. And the more assembler that I teach, the more that I learn about assembler, the more I just absolutely love what I do. I would probably have told myself back in those days, go learn the computer, become a computer scientist, which fortunately is what happened.”
Steven:
“Fantastic. And then one more final question to Jeff: you get to look into a crystal ball. The mist and the haze kind of start to spread and dissipate. Where do you see this platform, 10 years out from today?”
Geoffrey Decker:
“Well, don’t you think — I think you know and probably can verify this — that IBM actually has a plan for the mainframe for 50 more years, isn’t that right?
Steven:
We’ve got at least two more boxes in development. So that means we’ve got 17, then they’ll have 18 and 19 in at least development. So there’s always kind of three boxes: the one that they’re selling and then the two further out from that. So if you look at the current cycle, then that puts us at least another six to nine years out.
Geoffrey Decker:
Yeah, well, I think that people are going to learn that the mainframe is still here. They’re going to learn to respect it a lot more because of these capabilities. And they’re going to find out that AI on the Z17 and other upcoming machines is going to be a lot less expensive to run, a lot less water to be used, a lot less electricity to be used. I heard that those server — the big AI farms in Indianapolis — you can see them from space, and over some period of time they use three times the electricity the city of Atlanta uses. I couldn’t believe it. And that same work can be done on mainframes, and probably for a lot less money. So people are going to learn to respect the mainframe more than they even do now, and it’s much better now than it was even five years ago. I’ve seen a renaissance of excitement around the mainframe because of the Z17.”
Steven:
“Jeff, I can’t think of a better way to wrap up — a renaissance. You’re a renaissance man, my friend.”
Geoffrey Decker:
“Thank you.”
Steven:
“Thank you about the renaissance of the mainframe platform. You’ve been watching us here on the I Am a Mainframer Podcast. I’m your host as always, Steven Dickens. Please click, like, subscribe, and do all those things, and we’ll see you next time. Thank you very much for watching.”
Geoffrey Decker:
“Thank you.”
Narration:
“Thank you for tuning in to the Mainframe Connect Podcast and this episode in the I am a Mainframer series, sponsored by Phoenix Software International. Like what you heard, subscribe to get every episode or watch us online at openmainframeproject.org. Until next time, this is the Mainframe Connect Podcast.”
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