Senior Full Stack Web Engineer (Contract) - App Growth Team

The Wikimedia Foundation is looking for a full stack Senior Software web Engineer contractor to join the App Growth team within the Core Experiences engineering on a 3-month full-time contract.

This is not a native iOS or Android role. It is focused on web-first product experiences, APIs, and platform integrations that can be reused across mobile web and native app surfaces; to help us scale features across platforms and create compelling features that deepen reader engagement and increase user retention. You will build features that create natural handoffs between web and app and land users in exactly the right place — for example, prompting a reader to try a personalized reading list in the app, creating a game that is integrated within the apps as a webview; or when someone tries to edit, there is a smooth handoff to the web editing experience.

Important: We are a fully remote team at a global organization. To ensure there are enough opportunities to communicate, this role needs at least four hours of your workday to occur between 15:00 UTC and 21:00 UTC.

You are responsible for:

• Delivery and enablement - Delivery of medium complexity initiatives from technical discovery through delivery. Breaks down initiatives into features, drives estimation and manages scope. Identifies risks early, and helps the team make pragmatic tradeoffs across quality, velocity, maintainability, and user impact.
• Frontend Implementation - Create mobile Wikipedia product experiences that serve a global, multilingual audience across web and app surfaces. You can design and build accessible, adaptable, scalable, and reusable components.
• Backend Implementation - 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 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.
• Prioritization - Proactively identifies high-impact technical opportunities and risks across the engagement timeframe, works with the team to clarify priorities and sequencing. Actively keeps the team aligned on outcomes, capacity, and shared goals.
• Culture and standards - Complies with 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.

Qualities that are important to us:

• Clear communicator - You can explain your ideas simply and adapt your communication to different audiences across engineering, product, and non-technical audiences in both synchronous and asynchronous channels.
• Autonomy - Operates with high autonomy in a team setting and cross-team settings. You own your work end-to-end and practice a culture of responsibility and follow-through.
• Feedback - You give and receive feedback with curiosity and empathy. Helps others resolve misunderstandings productively.
• Builds strong relationships - Proactively brings the right people into discussions, identifies process improvements.
• Comfortable with ambiguity - You are comfortable with ambiguity and can collaborate to solve complex problems with pragmatic solutions. Connects ideas and can regularly balance trade-offs across related domains to create well-rounded solutions.
• Knowledge sharing - Strong knowledge-sharing practices, documents work for handover and consistently helps others understand and apply shared knowledge. You enjoy working with others to solve problems and are open to feedback. You inspire trust and progress through support, example, and thoughtful contributions.
• Outcome-oriented - You prioritize work that delivers value to users and aligns with organizational goals. You balance ideal solutions with the constraints of legacy, user expectations, and delivery needs.

Requirements:

• A Bachelor’s degree and 5-10+ years of related professional experience with significant experience building production web applications and services.
• Strong professional experience with JavaScript/TypeScript, JavaScript frameworks such as Vue.js, and backend languages such as PHP.
• 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 delivering in a self-driven, lean environment.
• Commitment to the Foundation’s Mission and Values.

Additionally, we’d love it if you have:

• 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 leveraging agentic coding to scale the work of small engineering teams.
• A 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.