Unix, Linux system administrator
In my work experience below you'll find over 15 years of Unix and Linux system administration including network administration, database administration and systems programming with Perl, shells (Bash, Csh, Tcsh and more). Part of being a system administrator required many things of me such as: team work, technical writing, project planning and problem solving. Also, a big part of system administration is learning new technologies on a regular basis. Some examples of useful technologies I've learned on the job are: Chef, Puppet, Cloudstack (Apache), AWS, S3, Nginx and much more.
As part of system administrator I was responsible for Web servers (Apache, IIS, and more), Database servers (Oracle, Sybase, Postgres, Mysql), file servers, ftp servers, ssh servers, build servers, Email servers in both software house environments and support environments.
Perhaps one of the best examples of administration I've encountered in my experience is Network administration which includes systems of all kinds, project management and infrastructure skills which have helped me become an important asset in many IT environments.