I'm system administrator administrator with experience wuith with Unix (FreeBSD, Solaris, Linux). I used to work as network administrator in the past.
I have practical knowledge of
Operating systems: Linux (all major distributions), FreeBSD, Solaris
Databases: Oracle Database, MySQL
Web services: Apache, Nginx, Lighttpd, Varnish, HAPROXY
Email: Postfix, Exim
Programming: PHP, BASH
Networking: iptables, squid, hp procurve, ip filter, dhcpd etc.
I am also supporting ready to go solutions like: CPANEL, ISPConfig, LDAPADMIN, Wordpress, Prestashop, Magento, AVS, OpenCart and similar stuff.