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 integral 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. 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
Contribute to deployment automation, CI/CD workflows, and service instrumentation
Participate in code reviews, design discussions, and technical planning
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
~ Experience in data processing systems such as graph databases, search indexes, or data processing pipelines
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📌 Senior Software Engineer (España)
🏢 Wikimedia Foundation
📍 España