Senior Full-Stack Engineer (back-end heavy)

We're looking for a Senior Full Stack Engineer to join our CRM team. We're responsible for the platform that powers all the communications that our users receive from Preply-emails, push notifications, and in-app messages. We're a cross-functional team of engineers, CRM Marketers, Data Scientists and Designers that work together to ensure every communication is timely, relevant, and drives meaningful engagement. Our focus is on creating reliable, scalable infrastructure that reaches the right users with the right message at the right time., You will work in a cross-functional team alongside the Engineering Manager, Marketers, Head of CRM, 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:

• Build and maintain frontend surfaces in React for CRM-facing experiences (e.g., notification and communication preferences);
• Own backend-heavy services end-to-end-from discovery and design through development, deployment, and iteration-to power emails, push, and in-app (bell) notifications;
• Partner daily with our Marketers and the Head of CRM to translate campaign and lifecycle needs into reliable, scalable technical solutions;
• Establish and promote best practices across backend and frontend, with a strong focus on correctness and safe delivery (avoiding mis-targeted or incorrect communications);
• Design architectures for high-traffic, data-processing workloads that determine when, what, and to whom we should send communications-while preparing the platform to scale with future growth;
• Balance speed and experimentation with strong engineering fundamentals, ensuring systems remain maintainable and resilient as requirements evolve;
• Continuously improve the quality, observability, and reliability of our communications platform, and help teammates grow through thoughtful feedback and high standards.

Do you have experience in UI?, This is a Full-Stack role with a focus on backend development, where you will spend the majority of your time. However, you need to be comfortable with ReactJS and be able to implement features in the frontend.

For backend development, we take a tech-agnostic approach, meaning we are open to considering candidates with diverse technology backgrounds, such as Java/Spring, Node.js/Express.js, Ruby/Ruby on Rails, Scala/Play, PHP, or Golang.

While Python is our primary programming language, prior experience with it is not mandatory. What truly matters is your enthusiasm for learning Python and your ability to adapt quickly to using it for product development., * Full-Stack Expertise: This role is backend-heavy, with most of your impact on building and evolving the services that power Preply's communications (email, push, and in-app/bell notifications), while also being able to comfortably pick up React/Typescript work when needed;

• Exposure to front-end tech: Hands-on experience with React to support and maintain the team's existing UI surfaces;
• Proven experience designing and operating scalable systems-comfortable with high-traffic environments and data processing pipelines where reliability and correctness matter;
• Ability to independently drive ambiguous work from discovery to delivery, balancing speed with quality-especially in areas where mistakes can impact large numbers of users;
• Strong stakeholder collaboration skills and the ability to explain technical trade-offs clearly to non-technical partners; effective communication in English at a B2 level or higher.

• An open, collaborative, dynamic and diverse culture;
• A generous monthly allowance for lessons on Preply.com, Learning & Development budget and time off for your self-development;
• A competitive financial package with equity, leave allowance and health insurance;
• Not in Barcelona? We offer an attractive relocation package to join us in our Preply Barcelona Hub;
• Access to free mental health support platforms;
• Access to Gympass-partnered wellness and gym centers throughout Spain to promote and support well-being and physical health;
• The opportunity to shape the lives of learners and tutors through language learning and teaching in 175 countries (and counting!).

At Preply, we're all about creating life-changing learning experiences. We help people discover the magic of the perfect tutor, craft a personalised learning journey, and stay motivated to keep growing. Our approach is human-led, tech-enabled - and it's creating real impact. 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. As a category-defining company, we're shaping what the future of learning looks like at global scale. Every Preply lesson sparks change, fuels ambition, and drives progress that matters. Joining Preply means helping define the future of education at global scale, and building something that truly matters for millions of people, every day., * Care to change the world - We are passionate about our work and care deeply about its impact to be life changing. * We do it for learners - For both Preply and tutors, learners are why we do what we do. Every day we focus on empowering tutors to deliver an exceptional learning experience. * Keep perfecting - To create an outstanding customer experience, we focus on simplicity, smoothness, and enjoyment, continually perfecting it as every detail matters. * Now is the time - In a fast-paced world, it matters how quickly we act. Now is the time to make great things happen. * Disciplined execution - What makes us disciplined is the excellence in our execution. We set clear goals, focus on what matters, and utilize our resources efficiently. * Dive deep - We leverage business acumen and curiosity to investigate disparities between numbers and stories, unlocking meaningful insights to guide our decisions. * Growth mindset - We proactively seek growth opportunities and believe today's best performance becomes tomorrow's starting point. We humbly embrace feedback and learn from setbacks. * Raise the bar - We raise our performance standards continuously, alongside each new hire and promotion. We build diverse and high-performing teams that can make a real difference. * Challenge, disagree and commit - We value open and candid communication, even when we don't fully agree. We speak our minds, challenge when necessary, and fully commit to decisions once made. * One Preply - We prioritize collaboration, inclusion, and the success of our team over personal ambitions. Together, we support and celebrate each other's progress.