Senior Full Stack Web Developer

Role overview A Europe-based, fully remote opportunity for a Senior Full-Stack Engineer to own every web-facing surface of a fast-growing AI-native language learning platform. The role is end-to-end product engineering, from shaping direction and running experiments to shipping features and measuring their impact on conversion, retention, and learner experience.

Responsibilities - Own the full web stack, including the marketing site, onboarding funnels, customer portals, web app, and internal tools. - Lead architecture, development, experimentation, and operations across all web applications. - Drive product decisions by contributing to vision, designing and running A/B tests, analyzing results, and iterating quickly. - Build adaptive, animated, mobile-first experiences optimized for conversion and delight. - Integrate with backend services via Swagger-style docs, plus authentication providers (Google/Apple SSO) and payment gateways (Stripe, PayPal, RevenueCat). - Set up and optimize analytics, tracking, and conversion funnels in partnership with Growth and Marketing. - Ship production-ready code end-to-end, from idea through deployment to monitoring.

Requirements - A product-first mindset with focus on user problems and business outcomes. - Extensive experience with TypeScript, React (hooks, context, state management), and Node.js. - Proficiency with modern full-stack tooling such as Next.js or equivalent, and CSS-in-JS or Tailwind. - Hands-on experience integrating auth providers (Firebase, Auth0), payment systems (Stripe, RevenueCat, PayPal), feature-flag platforms (LaunchDarkly, Flagsmith), and analytics tools (Amplitude, PostHog). - Strong UI/UX sensibility with attention to animation, micro-interactions, and conversion details. - Comfort working with RESTful APIs and collaborating closely with backend teams. - Data-driven approach with proven experience in A/B testing, funnel optimization, and analytics. - Ability to thrive in an async, distributed, written-first culture.

Nice to have - A portfolio of high-quality web projects and successful conversion experiments. - Prior experience at an early-stage or high-growth consumer product company.

Benefits and work setup - Equity in the form of stock options tied to impact. - 26 days of holiday plus bank holidays (34 days per year total). - Annual company off-site for the full team. - Health and wellness benefits via SafetyWing. - Access to a full AI toolkit, including productivity assistants and developer tools. - $1,000 annual education and learning budget. - Fully remote with a high-trust, async-first culture and minimal meetings.