Senior Software Engineer

Summary

Join the Wikimedia Foundation's MediaWiki Interfaces team as a Senior Software Engineer and make a global impact on hundreds of millions of Wikipedia users. You will design, develop, and maintain core components of the MediaWiki platform, driving technical excellence and operational efficiency. This role demands strong leadership, collaboration, and a commitment to continuous improvement. As a Senior Engineer, you will mentor team members, champion product metrics, and ensure alignment with user needs. The position is fully remote, requiring overlapping work hours with UTC+2 to UTC-7 time zones. This is an opportunity to combine technical expertise with a mission-driven purpose.

Requirements

• Commitment to the Foundation's Mission and Values
• Extensive experience in software engineering, ideally in high-impact web platforms and/or open-source
• Good understanding of HTTP
• Proficiency in PHP and JavaScript
• Deep understanding of software architecture, testing methodologies, and system design
• Strong experience in observability practices: setting up metrics, logging, monitoring, and alerting
• Familiarity with incident response, root cause analysis, and follow-up processes
• Experience working with CI/CD pipelines and automated test infrastructure

Responsibilities

• Designing, developing, and maintaining key parts of the MediaWiki stack
• 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
• Contributing to the adoption and advocacy of API-first development, and influencing best practices in system design, SLOs/SLAs, and OpenAPI Specification
• Championing product metrics: ensuring that key user journeys are instrumented and monitored to guide decisions and evaluate success
• Leading by example in code review, decision-making, and team culture - fostering transparency, empathy, and collaboration
• Improving and automating processes for identifying, tracking, and resolving production issues
• Collaborating with the Product team and the community to ensure technical solutions align with user and contributor needs
• Coaching and mentoring teammates to support continuous growth and confidence in both technical and interpersonal skills

Preferred Qualifications

• Experience developing frameworks (designing for reuse, extensibility, stability, and backward compatibility)
• Experience defining and working with SLAs/SLOs or other production reliability frameworks
• Prior experience with MediaWiki or Wikimedia projects
• Contributions to open-source software
• Experience with developer experience tooling, public APIs, or platform teams
• Experience working in a remote, distributed team