From The Free On-line Dictionary of Computing (8 July 2008) [foldoc]:
systems programmer
systems programming
<job> (sysprog) A generic job title that covers a variety of
specialist roles such as writing low-level code that talks to
directly to the operating system on a server.
Typical skills required are experience of specific operating
systems, networking (TCP/IP, ATM, Ethernet, DNS),
electronic mail (POP, IMAP, SMTP), web servers,
RDBMS, operating system and network security, and hardware
(SCSI, hard disks, and backup devices).
Contrast: system administration.
(1999-09-14)