Java developer; more active on Stack Overflow and some of the newer SE sites. Linux user since 1998.

Server administration isn't my main thing, but from time to time I do some of that too at work:

• Setting up & maintaining tools such as Subversion, Jenkins, Mediawiki, Confluence, PostgreSQL and MySQL; mostly on Linux (Ubuntu, Debian, Red Hat or Fedora).
• Deployment of Java webapps, with e.g. Tomcat, JBoss and Apache.
• Recently I've been learning about and using AWS as a platform for enterprise Java apps and for R&D infra. (Interesting how developer and sysadmin roles converge to some extent when cloud is your platform...)
• Automating setup of development and CI servers, using Puppet and common UNIX tools.