Senior Full stack Developer JS in London

We help people discover the magic of the perfect tutor, craft a personalised learning journey, and stay motivated to keep growing. We’ve just reached unicorn status with a $150M Series D, accelerating our vision to transform education through human-led, AI-enhanced learning. Today, 100,000+ tutors teach 90+ languages to learners in 180 countries - and we’re only getting started. Joining Preply means helping define the future of education at global scale, and building something that truly matters for millions of people, every day.

Our team builds scalable, resilient products using Python/Django on the backend and React on the frontend, all with one goal in mind: creating a smooth, meaningful experience for our learners and tutors. Whether you’ve worked with Java/Spring, Node.js, Ruby on Rails, Scala/Play, PHP, or Go, you’ll feel right at home here. Python experience isn’t required.

We make decisions based on data and real user feedback: running A/B tests, shipping iteratively, and constantly improving. We also put a strong focus on observability, monitoring, and metrics, so we can keep our systems healthy and continue optimizing at scale. At Preply, we ship 50–60 times per day, thanks to a solid CI/CD setup and a culture that values action over ceremony.

You will work in a cross-functional team alongside the Product Manager, Product Designer, UX Writers, Data Analytics, Technical Leads, Engineers and other cross-functional team members to deliver engaging features through A/B tests and build top-notch products, including, but not limited to:

• Develop and own backend features using Python/Django, supporting the creation of new backend services and designing, creating, and troubleshooting integrations with third-party vendors;
• Develop frontend features in React/Typescript, launched in our A/B experimentation framework;
• Take on the responsibility of writing services from initial concept to full-fledged deployment;
• Leverage previous experience to implement and socialise current best practices in frontend and backend;
• Data-driven approaches and experimentation are its heartbeats. Together with the product, data, and UX teammates, the team is responsible for value delivery, analysis, ideation, and focus;
• Strike a balance between delivering fast results and maintaining high-quality, sustainable systems;
• Embody a mindset of mastery by continuously seeking to improve your craft, delivering work of exceptional quality, and inspiring those around you to aim higher.

Full-Stack Expertise: This role is primarily backend-focused, with about 70-80% of the work on back-end development and 20-30% on the front-end, requiring solid backend expertise and well-rounded full-stack engineering skills; Exposure to front-end tech: A good understanding of React, Typescript, HTML5, and CSS; Exposure to architectural patterns of a large, high-scale web application (e.g., well-designed APIs, high-volume data pipelines, efficient algorithms); Communication Skills: Good at working with others and communicating effectively in English at a B2 level or higher; Minimum B2 English level.

A generous monthly allowance for lessons on Preply. A competitive financial package with equity, leave allowance and health insurance; Access to free mental health support platforms; The opportunity to shape the lives of learners and tutors through language learning and teaching in 175 countries (and counting!).

Growth mindset - We proactively seek growth opportunities and believe today's best performance becomes tomorrow's starting point. Raise the bar - We raise our performance standards continuously, alongside each new hire and promotion. One Preply - We prioritise collaboration, inclusion, and the success of our team over personal ambitions. Diversity, Equity, and Inclusion: We believe that the presence of different opinions and viewpoints is a key ingredient for our success as a multicultural Ed-Tech company. That means that Preply will consider all applications for employment without regard to race, color, religion, gender identity or expression, sexual orientation, national origin, disability, age or veteran status.