Description

The Wikimedia Foundation (WMF) is seeking an experienced Senior DBA to join our dedicated team. Our mission is to make the sum of all human knowledge freely available to everyone, and MariaDB serves as the backbone for storing this vast wealth of information. Our project sites rank among the most heavily visited on the internet, boasting an exceptionally high number of page views per engineer compared to other major platforms.

As a Senior DBA at the Wikimedia Foundation, you will be an integral part of a small, focused team of highly skilled and experienced engineers. In this critical role, you will be directly responsible for ensuring the unwavering health, availability, and optimal performance of our extensive database systems.

Your core responsibilities will encompass comprehensive troubleshooting of database issues, proactive database maintenance, meticulous performance tuning, ensuring robust high availability, managing complex replication setups, overseeing reliable backups, and implementing general optimization strategies. You will also be involved in rigorous benchmarking and thorough testing of new MariaDB and MySQL builds to ensure stability and performance.

WMF is a strong proponent of user privacy and the use of free and open-source software. Our large database cluster runs MariaDB exclusively on bare metal Linux hosts, reflecting our commitment to these principles.

The work you will do is absolutely crucial, directly supporting the access to knowledge for hundreds of millions of people worldwide. This is a unique and rewarding opportunity to make a significant positive impact on a global scale, all while contributing to a noble cause.

The ideal candidate should be open to occasional international travel, approximately 1-2 times per year.

Responsibilities

• Implement, maintain, and troubleshoot complex relational database systems across both production and staging environments.
• Manage database version upgrades, including thorough testing and collaborative work with upstream developers on bug identification and resolution.
• Configure and optimize database replication topologies, design efficient schema optimizations, and execute schema changes effectively.
• Implement proactive monitoring, perform in-depth debugging, and continuously improve query performance.
• Enhance the observability of our database infrastructure through robust alerting, comprehensive metrics, and effective monitoring solutions.
• Design and plan multi-datacenter replication topologies, ensuring adequate capacity and infrastructure.
• Actively participate in incident response, providing expert diagnosis and thorough follow-up on system outages or alerts across Wikimedia’s production infrastructure, and participate in an on-call rotation.
• Consistently embody and promote our core [link to WMF values page, if available] in all aspects of your work.

Qualifications

• Advanced level of hands-on experience in MariaDB or MySQL database administration as the primary production database, including managing replication topologies at scale.
• Deep knowledge of Linux operating systems and fundamental IO/data storage concepts, internals, and troubleshooting techniques (our production environment is exclusively Linux-based).
• Proven proficiency in SQL for querying, analysis, and optimization.
• Extensive experience in debugging complex query performance issues and designing efficient database schemas.
• Solid experience with MySQL high availability solutions and replication management tooling.
• Demonstrated experience in remotely managing bare-metal servers.
• 5+ years of practical experience in a hands-on DBA role as part of a collaborative team.
• Experience with high-traffic and highly available website architectures and operations.
• Excellent written and verbal communication skills in English.
• Demonstrated ability to work independently in a fast-paced environment while being an effective and collaborative member of a globally distributed team, utilizing ticket tracking systems and asynchronous communication tools effectively.
• B.Sc. or M.Sc. in Computer Science or equivalent relevant work experience.

Optional Qualifications

• Proficient automation, programming, and scripting skills (e.g., Bash, Python).
• Experience with LAMP stack technologies (PHP/HHVM, memcached/Redis) - familiarity with MediaWiki is a significant plus.
• Experience with advanced distributed storage and database systems (Swift, Ceph, Cassandra, etc.) is a major advantage.
• Proven experience in the architecture, design, and implementation of persistent data storage and query infrastructure.
• A strong track record of contributions to open-source projects is a major plus.

Note: If you feel strongly that you have what it takes for this role but don’t check 100% of the boxes—that’s okay—we encourage you to apply anyway and highlight what you can bring to the table.