Senior Software Engineer, Core Experiences

The Wikimedia Foundation is looking for a Senior Software Engineer to join the App Growth team within the Core Experiences engineering group. This role focuses on building web-first product experiences and APIs that enhance user engagement and retention across mobile and web platforms.

Responsibilities:

• Delivery and enablement - Consistently leads the team in the delivery of medium complexity initiatives (with support) from technical discovery through delivery. Breaks down initiatives into features, drive estimation and manage scope. Identifies risks early, and helps the team make pragmatic tradeoffs across quality, velocity, maintainability, and user impact
• Frontend Implementation - Improving the mobile Wikipedia product experiences that serve a global, multilingual audience across web and app surfaces. Leads system design for medium-sized projects and can design and build accessible, adaptable, scalable components
• Backend Implementation - Takes ownership of creating RESTful APIs, from schema and contract design through to monitoring and iteration, to serve simple but scalable data pipelines to mobile and web client experiences at scale. Ensures pipelines and APIs remain simple to consume, reliable to operate, and straightforward to evolve over time
• Quality, testing and observability - Consistently builds and improves systems & software that is easy to test, observe and debug. Instruments features that enable deeper analysis by Product Analysts
• Cross-functional collaboration - Partners with product managers, designers, analysts, and native app engineers to shape pragmatic solutions that balance user needs, technical constraints, platform expectations, and delivery timelines
• Prioritisation - Proactively identifies high-impact technical opportunities and risks across a quarter, partners with the team to shape priorities and sequencing. Actively keeps the team aligned on outcomes, capacity, and shared goals
• Mentorship - Actively supports the growth and success of others. Mentors engineers through thoughtful code review, technical design, pairing, delegation of meaningful ownership, and modeling strong engineering judgment. Encourage team mates to ask questions and raise concerns
• Culture and standards - Raises team standards in code review, technical design, testing, documentation, accessibility, observability, and decision-making - fostering transparency, empathy, and collaboration
• Operational Awareness - Plans work with awareness of downstream or upstream effects. Actively supports hiring and onboarding

Requirements:

• Bachelor's and 5+ years related professional experience with significant experience building production web applications and services
• Strong professional experience with JavaScript/TypeScript, Javascript frameworks such as Vue.js or React, and at least one backend language such as PHP, Python, Java, Go, or similar
• Experience building responsive or mobile-first web experiences, with attention to performance, accessibility, and usability
• Experience in designing and integrating with server-side APIs
• Experience working in a self-driven, lean environment
• Commitment to the Foundation's Mission and Values
• Experience adding webview-wrapped experiences to existing native mobile apps (iOS or Android)
• Experience in launching and maintaining native or cross-platform mobile applications (iOS or Android)
• Experience building mobile games or other interactive mobile experiences
• Experience with data science, machine learning, and/or AI (e.g., familiarity with prompt engineering, Jupyter notebooks experience, etc.)
• Familiarity with Wikipedia / wikitext / markdown editing or content management systems (e.g., MediaWiki, Drupal, WordPress)
• Experience with leveraging agentic coding to scale the work of small engineering teams
• Bachelor's, master's, or doctorate degree in computer science, management information systems, or STEM field (or equivalent certification)
• Prior experience with MediaWiki or Wikimedia projects
• A history of open source contributions
• Experience working in a fully remote, distributed team