Senior II Full-Stack Engineer (back-end heavy)

Stack

Responsibilities

• ▹Back-end development: design, build and evolve scalable backend systems with Python/Django, drive architectural decisions, create new services and own critical integrations
• ▹UI development: build frontend experiences in React/TypeScript, contribute to experimentation frameworks and frontend engineering best practices
• ▹Lead complex initiatives from discovery through deployment and own solutions throughout their lifecycle
• ▹Raise the engineering bar through mentorship, architectural reviews and best practices across frontend and backend
• ▹Data-driven product development with Product, Data and UX teammates to validate hypotheses and maximise customer value
• ▹System design: shape architectural direction for complex systems to improve scalability, reliability, maintainability and developer productivity
• ▹Prioritisation and decision-making: evaluate trade-offs and align technical investments with business objectives
• ▹Technical leadership: influence technical direction beyond your immediate scope together with engineers, managers and stakeholders

Requirements

• ▹Deep backend engineering expertise and the ability to contribute across the full stack and deliver end-to-end solutions
• ▹Experience designing and evolving large-scale web applications: well-designed APIs, distributed systems, high-volume data flows, scalable architectural patterns
• ▹Demonstrated ability to influence technical decisions and drive engineering best practices
• ▹Strong product mindset, able to translate ambiguous business challenges into scalable technical solutions using experimentation, data and customer insights
• ▹Proactive problem-solving in ambiguous situations
• ▹High level of self-organisation and ownership, with a track record of driving initiatives from concept to measurable outcomes
• ▹Excellent collaboration, stakeholder management and communication skills across engineering, product, design and data
• ▹English level B2 or higher
• ▹Experience mentoring engineers and contributing to code and design reviews
• ▹Understanding of observability, reliability and monitoring, and willingness to join the squad's on-call rotation (1 week every 5 weeks)
• ▹Deep, hands-on expertise in AI tools, especially in agentic AI SDLC

Soft skills

What we offer

• ▹Open, collaborative, dynamic and diverse culture
• ▹Generous monthly allowance for lessons on Preply.com, learning and development budget and time off for self-development
• ▹Competitive financial package with equity, leave allowance and health insurance
• ▹Relocation package to the Barcelona hub
• ▹Access to free mental health support platforms
• ▹Gympass-partnered wellness and gym centres throughout Spain

About the company

Preply creates human-led, tech-enabled learning experiences. The team uses Python/Django on the backend and React on the frontend, is tech-agnostic, runs A/B tests with a strong observability focus and releases 50-60 times per day.