For years, the narrative was that cloud-native would consign mainframes to history. To hear about the actual reality, Developer caught up with Dr Elizabeth Maxwell, Global Director of Mainframe Modernisation at BMC Software.
“There was a period where mainframes were being reviewed for replacement, but we have seen a complete pivot in this thinking,” says Maxwell.
Maxwell shares that in BMC’s yearly mainframe (MF) survey, an astonishing 97 percent of participants confirmed that the mainframe is a long-term platform for them and that it is being expanded for new workloads. She follows up saying, “the mainframe is here to stay and grow.”
That pivot is about recognising that the mainframe can be part of the same modern software machinery as everything else.
“Today’s mainframe is inclusive in both CI/CD and DevOps, simply folding into existing frameworks and utilising x86 systems tooling as part of the IT ecosystem and is inclusive of MF.”
In other words, it is not a tug of war between old and new; it is a practical integration where pipelines for mainframe code run on Jenkins or Azure DevOps, and developers work in VS Code or Eclipse rather than wrestling with a green screen.
Mainframe modernisation starts with the developer experience. Maxwell explains how an isolation effect held mainframe development back even while the hardware pushed forward. The way out has been to meet developers where they are: intuitive IDEs, intelligent code completion, integrated toolchains, and a culture that values delivery, speed and safety.
BMC AMI Code Insights sits inside the Workbench IDE for VS Code or Eclipse, surfacing diagrammatic and written explanations that make unfamiliar code understandable. It’s quite impressive how quickly behaviour can change when the friction falls.
“When we introduced BMC AMI DevX Workbench with Eclipse and VS Code interfaces for a financial services client, 20-25 percent of developers switched voluntarily within weeks,” Maxwell recalls. “The youngest developers ‘jumped in immediately,’ as their systems engineer told us. No mandate needed, just better tools.”
To quantify the results, teams report a 33 percent rise in active coding time and onboarding that takes half as long when an IDE replaces the green screen. One platform lead captured the cultural shift by saying the tools are “changing developer conversations from ‘This application is horribly built’ to ‘Hey, this is cool.’”
However, there is another reality to face. Much of the world’s business logic lives in code that predates most modern engineers. Maxwell cites an estimate of roughly 344 billion lines of COBOL in production, touching about 90 percent of the Fortune 500. Those programs can be weighty and intricate.
“It is like expecting someone to read Tolstoy’s War and Peace in one sitting and understand it all, then change and test it. Very hard indeed,” explains Maxwell.
GenAI is changing how teams approach this. With BMC AMI DevX Code Insights, developers get structured explanations and visual flows that accelerate mainframe understanding without sending intellectual property into public models.
The company is careful not to repeat mistakes seen elsewhere. AI can create what Maxwell calls an “AI Velocity Paradox”, where generated changes outpace the ability to deploy safely. BMC is thinking about the whole path, taking cues from the Model Context Protocol to connect the dots from diagnostics and fixes through testing, documentation, change control, and deployment.
The talent picture is improving as well. A few years ago, many worried that mainframe expertise would dwindle as veterans retired. That concern spurred action. Companies partnered with universities, set up graduate programmes and apprenticeships, and brought new developers into the fold.
In BMC’s survey, Millennials and Gen Z accounted for 37 percent of respondents, and the expectation is they will represent 66 percent in 2025. Those developers are used to VS Code, Git, and CI/CD. When those familiar tools are available on the mainframe, the platform becomes approachable rather than intimidating.
Respecting choice also helps. Maxwell shared the story of a colleague who had spent four decades on a green screen, travelling the world to tune COBOL and PL/I applications. He bristled when a modern interface, iStrobe, arrived. A few weeks later he didn’t want to go back.
Intuitive navigation, graphic views of performance hotspots, and lower effort made the difference. The broader lesson is that later-career developers often become champions for modern tooling when it helps them share knowledge and work faster. As Maxwell summarised, “choice wins hearts; results keep them.”
Moving beyond tools, many organisations want a structured way to modernise processes. BMC’s consulting teams start by listening. BMC uses Value Stream Mapping to uncover bottlenecks and align improvements with outcomes: faster deployments, less time spent debugging, fewer incidents; quicker onboarding and retention across hybrid teams; and a posture that integrates mainframes into enterprise DevOps without sacrificing stability. The approach is incremental: start with one application team, prove value, then scale.
Not every path involves keeping all the COBOL. Some choose to modernise specific modules that are costly, risky, or heavy on change, or to take advantage of zIIP processors. The key is not to turn modernisation into a rewrite that recreates technical debt in a new language.
The first step is to identify the right candidates using metrics in BMC AMI Code Insights, then break monoliths into manageable chunks to reduce risk and make testing straightforward. BMC AMI DevX Code Insights generates object-oriented Java code that follows modern design patterns.
“This isn’t ‘JOBOL’ (Java code that mimics COBOL’s structure) – line-by-line translations that just move the maintenance problem Java,” explains Maxwell. “BMC produces Java with comprehensive documentation explaining what the code does, thus capturing knowledge for the next person who touches the code.
“Most importantly, we preserve knowledge. Every conversion includes context-aware documentation generated by our AI, ensuring your logic isn’t lost in translation. The result? Teams inherit maintainable systems they can enhance, not technical debt in a new language.”
Modernisation should improve the developer experience and the system’s future, not simply rehouse complexity.
There is also a people dimension to attracting new talent while sustaining the pace of change. BMC believes the mainframe should feel like an extension of what early-in-career developers already know by offering VS Code, Git, and pipeline integration. Remove avoidable frustration by letting Code Insights GenAI explain legacy code in plain language, with visual maps and written context that capture tribal knowledge for the next person. Create hybrid teams, so experience and fresh perspectives mix every day. Then connect the work to business outcomes and track what matters with DORA metrics.
Underpinning all of this is a mindset shift. Stop treating the mainframe as separate, or as a problem to be replaced, and start bringing it into the same fabric as the rest of your software estate. Put pipelines on Jenkins or Azure DevOps. Use IDEs like VS Code and Eclipse. Lean on GenAI where it speeds understanding and safeguards intellectual property. When you do, the tone on the team changes from resignation to curiosity and you rediscover a platform that earns its keep by doing the hard things dependably.
“Mainframes are evolving platforms for modern innovation,” explains Maxwell. “Humans will direct the production line of addressing incidents, but the interaction will be guiding rather than doing.”
Want to learn more about mainframes from BMC? Check out Live Demo & Hands On: Navigating the BMC AMI DevX Platform to Understand Code Faster Using AI taking place virtually on Wednesday 12th November at 10:00am GMT.