Senior Software Engineer

Summary

Join the Wikimedia Foundation's MediaWiki Interfaces team as a Senior Software Engineer and contribute to the platform powering Wikipedia and its sister projects. This role combines technical expertise with impactful work, enabling you to design, develop, and maintain key parts of the MediaWiki stack. You will drive technical quality, lead by example, mentor team members, and collaborate with product teams and the community. The position requires extensive software engineering experience, proficiency in PHP and JavaScript, and a deep understanding of software architecture and testing methodologies. The team is fully remote, with working hours overlapping UTC+2 to UTC-7 time zones. This is a unique opportunity to make a significant contribution to a global platform.

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

Benefits

• The anticipated annual pay range of this position for applicants based within the United States is US$ [ 109,047 ] to US$ [ 169,455 ] with multiple individualized factors, including cost of living in the location, being the determinants of the offered pay
• For applicants located outside of the US, the pay range will be adjusted to the country of hire
• We neither ask for nor take into consideration the salary history of applicants
• The compensation for a successful applicant will be based on their skills, experience and location
• All applicants can reach out to their recruiter to understand more about the specific pay range for their location during the interview process