Senior Software Engineer, Wikidata Platform

Summary The Wikimedia Foundation is seeking a Senior Software Engineer to join the team supporting the Wikidata Platform — the structured data backbone of Wikimedia projects and a key part of the global open knowledge ecosystem. You’ll help scale and sustain the Wikidata Query Service (WDQS) and related platform services that power tools, features, communities, and research efforts across Wikimedia projects and beyond. This role combines backend engineering and operations ownership. You’ll implement high-scale, production-grade services while ensuring performance, reliability, and maintainability. Working closely with the technical and product leads, you’ll contribute to shaping the future of how the world queries and interacts with structured, linked data. Important: We are a fully remote team. Your working hours will need to overlap with UTC+1 to UTC-5 time zones to accommodate members of your team around the world. With 14:00 UTC to 17:00 UTC being the team's overlapping hours. What You’ll Do • Design, build, and maintain backend systems and APIs that power Wikidata’s query infrastructure • Improve reliability, observability, and automation of the Wikidata Query Service and data pipelines • Integrate Wikidata Platform services with other systems and data sources across Wikimedia • Collaborate with SRE, data engineers, and product teams to ensure stability and scalability under growing usage • Monitor production systems, respond to operational incidents, and proactively identify and resolve bottlenecks • Support platform migrations and system upgrades (e.g., triple stores, streaming ingestion) • Contribute to deployment automation, CI/CD workflows, and service instrumentation • Participate in code reviews, design discussions, and technical planning • Document systems and share knowledge with team members and Wikimedia’s broader technical community Skills and Experience We’re Looking For • 5+ years of experience as a backend or platform engineer working on distributed systems or data platforms • Deep understanding of database and/or knowledge graph representation technologies and standards • Proficiency in Java, C++, or other systems languages. Ability to set up, scale, and investigate systems is more important than expertise in a particular language. • Experience building and operating production-grade services with SLOs - good appreciation of scalability, performance, reliability and other non-functionals • Familiarity with modern observability tools (metrics, logging, tracing) • Experience in data processing systems such as graph databases, search indexes, or data processing pipelines • Ability to work collaboratively across disciplines and communicate clearly across technical and non-technical audiences • A commitment to learning, resilience, and contributing to a mission-driven engineering culture Nice to Have • Experience working with knowledge graphs or RDF/SPARQL • Familiarity with streaming data systems (e.g., Kafka, Flink) • Comfort with CI/CD pipelines and containerization tools (e.g., Docker, Kubernetes) • Experience in open source or open knowledge communities • Familiarity with Wikimedia technologies, Wikidata, or MediaWiki About the Wikimedia Foundation The Wikimedia Foundation is the nonprofit organization that operates Wikipedia and the other Wikimedia free knowledge projects. Our vision is a world in which every single human can freely share in the sum of all knowledge. We believe that everyone has the potential to contribute something to our shared knowledge, and that everyone should be able to access that knowledge freely. We host Wikipedia and the Wikimedia projects, build software experiences for reading, contributing, and sharing Wikimedia content, support the volunteer communities and partners who make Wikimedia possible, and advocate for policies that enable Wikimedia and free knowledge to thrive. The Wikimedia Foundation is a charitable, not-for-profit organization that relies on donations. We receive donations from millions of individuals around the world, with an average donation of about $15. We also receive donations through institutional grants and gifts. The Wikimedia Foundation is a United States 501(c)(3) tax-exempt organization with offices in San Francisco, California, USA. As an equal opportunity employer, the Wikimedia Foundation values having a diverse workforce and continuously strives to maintain an inclusive and equitable workplace. We encourage people with a diverse range of backgrounds to apply. We do not discriminate against any person based upon their race, traits historically associated with race, religion, color, national origin, sex, pregnancy or related medical conditions, parental status, sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, or any other legally protected characteristics. The Wikimedia Foundation is a remote-first organization with staff members including contractors based 40+ countries*. Salaries at the Wikimedia Foundation are set in a way that is competitive, equitable, and consistent with our values and culture. The anticipated annual pay range of this position for applicants based within the United States is US$ 116,633 to US$ 181,243 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. *Please note that we are currently able to hire in the following: US States: Arizona, California, Colorado, Connecticut, District of Columbia*, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Puerto Rico*, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin and Wyoming (*US Territory or Federal District) Countries: Brazil, Canada, Colombia, Germany, Ghana, India, Indonesia, Italy, Kenya*, Mexico, Morocco, Netherlands, Poland, Singapore*, South Africa, Spain, Switzerland and the United Kingdom. Our non-US employees are hired through a local third party Employer of Record (EOR) and must have current work authorization in their location. (*citizens/permanent residents only) We periodically review this list to streamline to ensure alignment with our hiring requirements. All applicants can reach out to their recruiter to understand more about the specific pay range for their location during the interview process. If you are a qualified applicant requiring assistance or an accommodation to complete any step of the application process due to a disability, you may contact us at recruiting@wikimedia.org or +1 (415) 839-6885. More information U.S. Benefits & Perks Applicant Privacy Policy Wikimedia Foundation What does the Wikimedia Foundation do? What makes Wikipedia different from social media platforms? Our Projects Our Tech Stack News from across the Wikimedia movement Wikimedia Blog Wikimedia 2030