Senior Software Engineer at Wikimedia Foundation

Feedinkoo; United States; Remote; USD 109,000 - 169,000; Full time

Job summary

Wikimedia Foundation is seeking a Senior Software Engineer to join the MediaWiki Interfaces team. Design and build critical parts of the MediaWiki stack, with a focus on the web API and integration interfaces used by Wikipedia and sister projects.

The role emphasizes code quality, observability, and scalable architecture while mentoring teammates. This fully remote position requires overlap across UTC+2 to UTC-7 time zones to coordinate with a global team.

Qualifications

• Extensive experience in software engineering, web platforms and open source.
• Proficient in PHP and JavaScript; strong HTTP knowledge.
• Deep understanding of software architecture, testing methodologies, and system design.
• Experience with observability, metrics, logging, monitoring, and incident response.
• Experience 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.
• Autonomously creating proofs of concept, writing design documents, and breaking down complex projects into actionable tasks.
• Contributing to API-first development and OpenAPI specification practices.
• Championing product metrics and instrumenting key user journeys to guide decisions.
• Leading by example in code review, decision-making, and team culture.

Skills

PHP

JavaScript

HTTP

System design

Observability

CI/CD

Incident response

Testing methodologies

Job description

Senior Software Engineer – MediaWiki Interfaces

The Wikimedia Foundation is looking for a Senior Software Engineer to join the MediaWiki Interfaces team. MediaWiki is the open‑source platform that powers Wikipedia and its sister projects – impacting hundreds of millions of Wikipedia users across the globe. Our team owns the web API and other integration interfaces of MediaWiki, enabling other teams to create features that allows users to access, edit, and consume knowledge efficiently and reliably. The MediaWiki Product Insights have more information on the kind of work the group undertakes. This role offers a unique opportunity to combine technical depth with mission‑driven impact. 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. Your working hours will need to overlap with UTC+2 to UTC-7 time zones to accommodate members of your team around the world.

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.

Qualities We Are Looking For

• Clear communicator: You explain complex ideas simply and foster shared understanding across engineering, product, and non‑technical audiences.
• Outcome‑oriented: You prioritize work that delivers value to users and aligns with organizational goals. You balance ideal solutions with the constraints of scale, legacy, and user expectations.
• Accountable: You own your work end‑to‑end and help establish a culture of responsibility and follow‑through.
• Candid and respectful: You offer feedback directly, constructively, and with care – and invite the same in return. You support growth by challenging ideas, not people.
• Collaborative leadership: You inspire trust and progress through support, example, and thoughtful contributions.

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.

We’d Love It If You Have

• 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.

Salary

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.

Equal Opportunity Employer

As an equal‑opportunity employer, the Wikimedia Foundation values having a diverse workforce and continuously strives to maintain an inclusive and equitable workplace. We encourage people with a diverse range of backgrounds to apply. We do not discriminate against any person based upon their race, traits historically associated with race, religion, color, national origin, sex, pregnancy or related medical conditions, parental status, sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, or any other legally protected characteristics.