Deutsche Bahn recently posted a job posting for an IT administrator with special skills. X user konkretor recently discovered a job posting for an IT professional familiar with legacy operating systems, including Windows 3.11 and MS-DOS. The job posting has since been removed, but according to the user, the position was related to railway display panels widely used in Germany.
Tom's Hardware understands that candidates for this position will be in charge of machines running 166MHz processors and 8MB of memory, which are used to display important train technical data to operators in real time.
Relying on ancient software for critical infrastructure may seem like a security risk, but the opposite is true. Traditional hardware and operating systems have been extensively probed and patched in their heyday and are battle-tested. The same goes for the software written for these platforms - they have been refined to the point where they can perform their intended tasks smoothly. If it's not so bad that it can't be used, there's no need to upgrade.
It could also be said that outdated platforms are less likely to be targeted by modern cybercriminals, and the most affordable way for hackers is to master some new systems that are still used by millions of people.
Legacy systems are much more common than most people realize and are still used to run mission-critical systems. Some aircraft manufacturers still use floppy disks for service updates on older aircraft. For years, Chuck E. Cheese used floppy disks to run its animations, and it was only in 2019 that the U.S. military stopped using 1970s-era IBM Series-1 computers in nuclear weapons systems.
It's unclear whether the German rail operator found the employees it wanted or deleted the job posting out of embarrassment. If your grandfather is looking for a new job, maybe leave him a message and ask him to send over his application.