Senior Full-stack Engineer (backend-heavy)

Description

The company makes language learning more personal by helping people find the right tutor, plan their learning path and stay motivated. Its model combines human teaching with technology.

The company has raised a $150M Series D and reached unicorn status. Its 100,000+ tutors teach 90+ languages to learners in 180 countries, and the company says it is still early in its growth.

The team builds scalable, resilient products with Python/Django on the backend and React on the frontend, aiming for a smooth experience for learners and tutors.

Python experience is not required. Engineers coming from Java/Spring, Node.js, Ruby on Rails, Scala/Play, PHP or Go are welcome.

Decisions are driven by data and user feedback, using A/B tests, small iterative releases and close monitoring. The company deploys 50-60 times per day on a mature CI/CD setup.

Over 90% of engineers already use AI coding tools, and the company is moving toward more autonomous, AI-augmented development. Engineers get access to the best available tools and room to experiment.

The company publishes posts on its Engineering Blog about many of its technical challenges.

Responsibilities

• Work in a cross-functional team with product managers, product designers, UX writers, data analysts, engineering managers, engineers and other stakeholders to deliver results for learners and tutors.
• Build and own backend features in Python/Django, including new backend services, and design, build or troubleshoot integrations with third-party vendors.
• Build and improve frontend experiences in React/TypeScript, support experimentation frameworks and help establish frontend best practices.
• Lead complex projects from discovery to deployment, owning solutions over their lifetime and balancing immediate product needs with long-term sustainability.
• Raise engineering standards through mentoring, architecture reviews and adopting good practices across frontend and backend work.
• Partner with product, data and UX colleagues to find opportunities, test hypotheses and deliver value through experiments and measurable outcomes.
• Shape the architecture of complex systems to improve scalability, reliability, maintainability and developer productivity.
• Handle ambiguity, weigh trade-offs and align technical investments with business goals and customer impact.
• Influence technical direction beyond your own scope, working with engineers, managers and stakeholders to reach alignment and deliver successfully.
• Keep raising quality through craftsmanship, curiosity, learning and helping others grow.
• This list is not exhaustive, and the role may cover other initiatives that drive customer and business impact.

Requirements

• This is a backend-heavy full-stack role, with about 60% of the work on the backend and 40% on the frontend.
• Hands-on experience with agentic AI, and the ability to influence the team beyond code generation. Keep your own judgment for architecture, business logic and security, use AI as a thought partner, and set up quality gates and safety nets. Propose AI-native alternatives to existing workflows.
• Experience designing and evolving large-scale web applications, including well-designed APIs, distributed systems, high-volume data flows and scalable architectural patterns. You make sound trade-offs between short-term delivery and long-term sustainability.
• A record of influencing technical decisions, promoting engineering best practices and contributing to architectural direction within your team.
• A strong product mindset. You turn ambiguous business challenges into scalable technical solutions, guided by experiments, data and customer insight.
• You work independently on complex technical and product problems and know when to bring others in to increase impact.
• You are self-organised and take ownership, with a track record of driving initiatives from concept through delivery to measurable outcomes.
• Strong collaboration, stakeholder management and communication skills across engineering, product, design and data. English at B2 level or higher.
• Experience working in a cross-functional team, contributing to code and design reviews, and raising the bar through knowledge sharing and technical leadership.
• An understanding of observability, reliability, monitoring and operational best practices, and willingness to join your squad's on-call rotation of one week in every five.

Conditions

On-call duty in your squad: one week in every five weeks.

The place of work is the Barcelona hub, and a relocation package is offered to candidates who are not in Barcelona and want to join the team there.

Benefits

• A generous monthly allowance for taking lessons on the company's platform.
• A Learning and Development budget and time off for self-development.
• A competitive financial package that includes equity, leave allowance and health insurance.
• Free access to mental health support platforms.
• Access to gym and wellness centres across Spain through a Gympass partnership.
• The chance to shape the lives of learners and tutors through language learning and teaching in 175 countries and counting.