Mainframe - Present and Future - 2025 and Beyond

If you haven't used z/OS (Operating system) or worked in a z/OS shop, you will never understand how fundamentally different mainframe environments are. Once you've been exposed to the mainframe way of doing application development, the abstract representation of the entire application and everything that supports it starts to live in your head and you start to realize how incredibly backwards a lot of modern cloud scale stuff is.

In Mainframes, all kinds of support considerations have been built into nearly every component of the environment. The error message culture alone eliminates all the frantic googling that most non-mainframe engineers are used to doing when they get error messages. The OS and applications are expected to emit error and warning codes, which translate to actual English text that tell you what happened, and what to do about it. If necessary, IBM support can remotely debug, test any component in the frame after it's been automatically taken out of service.

If any of this detailed documentation refers to some operating system data structure you've never heard of, well, those are all documented in the MVS data area manuals, volumes 1-4, with convenient "eyecatcher" human-readable four character strings so you can quickly identify them in a hexdump of the operating system's memory. Nearly every single thing the OS outputs is also documented in the system message manuals, volumes 1-10. Don't even need to bookmark it, everything's immediately available via the master documentation index at ibm.com/docs/zos.

Present

The organizations which still use mainframe tend to be the biggest, most complex and sclerotic organizations on the planet. IBM is going to be enjoying the benefits of what it built decades ago for decades to come.

The fact is that mainframe is an effective technology stack. But more importantly, IBM has become extremely good at both keeping it up to date while also owning the best ways of modernizing it.

Future

IBM is good at making sure they control the path away from mainframe. The best, simplest and lowest risk approaches to getting off legacy code on mainframe are either developed by or bought by IBM. By enabling Linux on mainframe and providing straightforward migration paths from legacy code to that platform, IBM (and its many partners) ensures that modernization of mainframe for the most part means staying on mainframe. This has gone through multiple phases and taken lots of forms over the years but really, IBM has done a stupendous job of ensuing that the future of mainframe is usually mainframe.

The advent of AI code interpretation and generation is another example of this. IBM has already announced their own AI tooling to help customers make the migration to mainframe Linux faster and smoother.

The challenge for any AI startup or professional services company wanting to help customers move away from mainframe is that the people best placed to sell those tools are... IBM and its partners.

Technology change can only ever happen successfully at the rate an organization is able to change along with it. IBM is going to be enjoying the benefits of what it built decades ago for decades to come.

What do you think? Please share your comments.