In IBM mainframes, "systems programmer" (sysprog) traditionally means "system administrator". Part of the reason for that, is a systems programmer was expected

In IBM mainframes, "systems programmer" (sysprog) traditionally means "system administrator". Part of the reason for that, is a systems programmer was expected to be accomplished at assembler, which was used to write user exits (to customise the behaviour of the operating system to meet the needs of each site) and even patches to the OS code (SYSMODs). Operators were responsible for day-to-day running of the system (startup, shutdown, mounting and unmounting tapes and removable disk packs, changing forms in printers, starting jobs, resolving minor technical problems). Sysprogs were responsible for installation, configuration, customisation, upgrades, troubleshooting more complex problems, etc. Over time, the need to customise the code of the OS declined, and IBM made the OS much harder to modify by taking away customer access to source code (IBM's 1983 "Object Code Only" announcement) – so contemporary IBM mainframe system administration involves much less programming than it used to, but the name has stuck. Also, you no longer have to write user exits in assembler – C is supported (e.g. using IBM Metal C), as is PL/X (if you work for IBM, or one of the small handful of ISVs who ordered IBM's PL/X compiler during the brief period they were offering it to them)