Senior Software Engineer, MediaWiki Summary
The Wikimedia Foundation is looking for a Senior Software Engineer to join the MediaWiki Platform team. MediaWiki is the open-source platform that powers Wikipedia and its sister projects - impacting hundreds of millions of Wikipedia users across the globe.
The team’s mission is to provide a solid foundation for feature teams to build on. It focuses on performance, reliability and scalability, helping to ensure broad and equitable access to free knowledge.
As a Senior Engineer, you will not only write robust code but also lead by example, prioritize high-impact work, support better decision-making through metrics and observability and foster a culture of accountability, transparency, and continuous improvement.
Important: We are a fully remote team. Driving technical quality and operational excellence by defining and reinforcing standards in testing, observability, and system reliability;
Comfortably and autonomously creating proofs of concept, writing design documents,



and breaking down complex projects into actionable tasks to support less experienced team members;
Qualities we are looking for:
You explain complex ideas simply and foster shared understanding across engineering, product, and non-technical audiences;
Extensive experience in backend software engineering;
Familiarity with platform or infrastructure products that serve internal or external engineering teams;
Deep understanding of software architecture, testing methodologies, and system design;
Experience working with CI/CD pipelines and automated test infrastructure.
Additionally, we’d love it if you have:
Proficiency in PHP and JavaScript;
Prior experience with MediaWiki or Wikimedia projects;
Contributions to open-source software;
Experience working in a fully remote, distributed team.
The Wikimedia Foundation is the nonprofit organization that operates Wikipedia and the other Wikimedia free knowledge projects. We host Wikipedia and the Wikimedia projects,

📌 Senior Software Engineer JS (España)
🏢 Wikimedia Foundation
📍 España