If you are looking to get involved in improving the underlying infrastructure of Wikimedia projects, the Operations team may be just what you are looking for. Anyone can contribute to the effort to make Wikimedia's servers and software faster and more efficient. Many tasks are available for you to start contributing to right away.
The Operations Team
The operations team, or ops team for short, is the group of people that maintain Wikimedia's servers and run its 800+ individual wikis. Also known as the system administrators, they are in charge of making sure the MediaWiki software runs smoothly on all the wikis, regulating system resource use, maintaining Wikimedia's hardware and software, and creating and closing wikis (although these tasks can also be handled by other users with shell access).
Wikimedia's servers are hosted in four locations around the globe: Ashburn, VA, Dallas, TX, San Francisco, CA, and Amsterdam, the Netherlands. The primary data center is the one in Ashburn. Wikimedia's servers run Ubuntu and Debian, and the main software for Wikimedia projects is MediaWiki, a PHP-based application.
See also this presentation from January 2014 (16min). Even if some details have changed, it is still a good introduction.
The operations team manages more than eighty code repositories to maintain Wikimedia's server tools and infrastructure.
Essential skills for becoming an operations member include server software and hardware knowledge, good communication skills, and experience with MediaWiki and puppet. Puppet is a tool used by Wikimedia to maintain and configure its computer clusters. To be a useful operations member, you will need to learn puppet.
To work with the operations team, you need to acquire permissions (or less likely permissions) to perform certain tasks, although many tasks can be worked on without NDA access. These permissions are granted on a case-by-case basis after confirming the requestor's credentials and making sure he or she has signed the NDAs.
Acquiring privileged access:
How to Find Tasks
To start working with the operations team, you can find tasks at Phabricator. Phabricator is a web-based system used for finding and tracking bugs that the Wikimedia Foundation uses. To help, you can go to the issue list and work with others to resolve issues.
It is best to find some tasks that you are qualified to help on, acquire your Labs account, create a Phabricator account using it, and submit changes to the Puppet repository for review in Gerrit. Read the Puppet coding article to better understand how Puppet is used in managing the configuration of Wikimedia sites.
Most users do not need shell access to contribute.
How to Test Changes
After you have made your changes, it is time to test them in Wikimedia Labs. Labs is a project designed to make it easier for the community to test improvements to the Wikimedia infrastructure. Many tutorials are available.
How to Propose Changes
The final step is to propose your changes to the community using Gerrit. Gerrit is a system allowing community members to review proposed code changes and implement them.