Senior Software Engineer, Wikidata Platform

Wikimedia Foundation; Poland; Remote; PLN 291,000 - 438,000; Full time

Job summary

A leading nonprofit organization is seeking a Senior Software Engineer for remote work. The role involves backend engineering for the Wikidata Platform, focusing on scaling and supporting data services. Candidates should have strong experience in distributed systems, Java or C++, and a collaborative mindset. This position offers a meaningful opportunity to contribute to open knowledge.

Qualifications

• 5+ years of experience as a backend or platform engineer working on distributed systems or data platforms.
• Deep understanding of database and knowledge graph representation technologies and standards.
• Proficiency in Java, C++, or other systems languages.

Responsibilities

• Design, build, and maintain backend systems and APIs for Wikidata.
• Collaborate with SRE, data engineers, and product teams.
• Monitor production systems and resolve operational incidents.

Skills

Backend or platform engineering

Distributed systems

Database technologies

Java or C++ proficiency

Production-grade services

Modern observability tools

Graph databases understanding

Collaborative work

Tools

Docker

Kubernetes

Kafka

Flink

Job description

Senior Software Engineer, Wikidata Platform

Remote

Overview

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.

Note: We are a fully remote team. Your working hours will need to overlap with UTC+1 to UTC-5 time zones to accommodate team members around the world. Overlapping hours commonly include 14:00–17:00 UTC.

What You’ll Do

• Design, build, and maintain backend systems and APIs that power Wikidata’s query infrastructure
• 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 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
• Familiarity with modern observability tools (metrics, logging, tracing)
• Understanding of 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 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.

Equal Opportunity Employer: The Wikimedia Foundation values a diverse workforce and is committed to an inclusive and equitable workplace. We do not discriminate on the basis of race, religion, color, national origin, sex, pregnancy or related conditions, sexual orientation, gender identity or expression, age, disability, or any other legally protected characteristics.