Full-stack Engineer - Senior in Madrid


Share offer

Job Description

Busuu is one of the top EdTech companies in the world and has won numerous awards for its innovation and impact in language learning.

Busuu’s vision is to empower everyone in the world through languages. We are the world’s largest online community for language learning, with more than 120+ million users from 190 countries, growing at up to 20,000 new users per day. We make learning a language easy by combining AI-powered courses with instant feedback from our global community of native speakers and live tutoring from qualified teachers across the world.

In January 2022, Busuu was acquired by one of the largest EdTech companies in the world, Chegg (NYSE:CHGG). Being part of Chegg will help us to accelerate our growth and achieve our vision even faster.

What does a Full Stack Engineer do at Busuu?

As a Full Stack Engineer, you will be working on a new and exciting initiative at Busuu. You will work on features from ideation, implementation, and release collaborating with all departments of the company. Once released to users your work will be seen by millions and from there you will measure, evaluate, and evolve what you just released.

You'll be working on implementing new features working in sprints. We're looking for people who have passion for the user (UI, UX) but also who are interested in performance and code scalability. We're looking for candidates who have a desire to work with Front-end technologies using frameworks like React as much as working with Back-end technologies.

You will ship often without sacrificing the quality of code and you'll collaborate extensively with the other engineers in the team. We are a team of experienced developers that rely heavily on data to make decisions about where to go next. We strive to write simple and readable code while still developing highly scalable systems.

What we are looking for in a Senior FullStack Engineer:


  • Experience with writing performant and scalable services in NodeJS with TypeScript.
  • Good expertise in data modeling and performance optimisation using relational databases (we use MySQL and PostgreSQL).
  • Solid knowledge of REST API design.
  • Exposure to the architecture of high-traffic web platforms.
  • Experience with testing methodologies, performance debugging, and benchmarking.

Nice to have:

  • Experience working with PHP/OOP and experience with a modern web framework (we use Symfony 3 to 5).
  • Experience with a modern framework such as NestJS and solid understanding of how to model and architect backend services and requirements.


  • Strong knowledge of ES5 and ES6.
  • Experience and understanding of the React ecosystem.
  • Experience with testing methodology using Mocha, Jest, or similar.
  • Knowledge of HTML Semantic and CSS.
  • Experience in building complex layouts and working with responsive applications.
  • Awareness of cross-browser compatibility issues and client-side performance considerations.
  • Demonstrated design and UX sensibilities.

At Busuu we want to ensure that you have access to some great benefits:

  • We have an amazing office which is available for you to work from if you would like to do so, this is completely optional at the moment in the current environment. If you would like to be in the office we have put in place lots of important social distancing practices to ensure you are safe to meet with your colleagues in person
  • The office is well-equipped with free breakfast, plenty of snacks, fresh fruit and free dinner of your choice if you need to stay late
  • Social interaction is really important to us so we have lots of remote activities for you to join into such as team events, socials, online weekly quiz, etc
  • There is a personal training budget just for you, so you can learn more in your field, attend virtual conferences and events that you find interesting
  • To keep you active and help your mindfulness we offer weekly virtual yoga sessions
  • Busuu offers a great private health insurance scheme
  • We like to support our teams with their work life balance so we offer flexible working hours

What happens next

We aim to have a simple and speedy hiring process and we want to make sure that we are right for you as much as the other way around. The hiring process for Full Stack Engineer is the following steps:

  1. CV application review - We will review it as quickly as possible.
  2. Let’s chat - Quick chat with our recruiter about your experience and the role.
  3. Culture fit interview - Video call with the Engineering and Product Manager.
  4. Fullstack Take home test - We will send you a technical test to complete in your time.
  5. Task Review & Technical interview - Technical interview questions with the team.

Our platform is for everyone, and so is our workplace. We pride ourselves on embracing our differences, whether they're cultural, racial, religious or otherwise. This means each one of us comes to work knowing that we have a voice – and a safe, judgement-free zone to speak freely.

If you like the sound of that, join us. We'd love to hear what you have to say.


About Busuu

  • Social Network

  • London, UK

  • 50-200

  • 2008


Other full-stack developer jobs that might interest you...