JavaScript Developer

  • Engineering / Infrastructure
  • Madrid, Spain

JavaScript Developer

Job description

Are you a JavaScript Developer who loves writing readable / well-structured JS code?

You'll be working on the frontend + Chrome Extension of one of our new supercool Digital Marketing Analytics tools making some improvements on this extension and also some debugging so it's really JS for writing code.

In 2025, you will be able to refill your organic shampoo straight out of the shower by touching the wall. Your next favorite sneakers will be guessed and delivered by cyber-birds. Your coffee machine will automatically customize your coffee based on your mood. Do you want to help customers to have the best shopping experience? Heck Yeah!

Scalefast helps amazing brands develop a successful Direct-to-Consumer online business. Our next-generation technology platform is built to optimize modern eCommerce. Our end-to-end infrastructure includes global merchant-of-record agreements, fulfilment, subscription, loyalty programs, and finance functions to deliver new revenue and delightful brand experiences with a proven track record with global brands.


At Scalefast we are constantly looking for talented people to join our projects. Our start-up environment is very open-minded, we love to test and implement new ideas. If you think you are ready to enjoy your work and be part of our big family, keep reading to see how you match our current needs.


What can I expect at Scalefast?

  • Competitive salary and a career path adapted to each person's abilities and experience within a company that is growing continuously
  • 2 days a week working from home
  • A flexible schedule and total conciliation between work and family life including reduced timetable during one month in summer
  • Become part of a multi-cultural happy family where you can contribute with your experience and learn from the experience of others
  • Work with amazing brands
  • Get the opportunity to influence the future of our services and platform
  • Excellent working environment with frequent social activities (hackathons, Spartan races, quarterly whole-team social event)
  • Central Madrid office located an 8-minute walk from Atocha train station, with a bus stop and BiciMad station right outside the office
  • Kitchen and dining facilities as well as a fully stocked games room with games consoles etc. - great to disconnect from work for a while and have fun with your colleagues.
  • Discounted parking space in the office building if you’re coming by car, bicycle parking for those worried about their carbon footprint.

Job requirements

In our Air360 team you will:

  • Work in the development of our new product, the Air360 Marketing Analytics tool that specializes in performance-enhancing, mobile and eCommerce experience analytics,
  • Work with cross-functional teams to create and deliver new experiences for our clients.
  • Research and analyse new tendencies and technologies to improve the tool.
  • Build new features and ensure the quality of the platform.
  • Share and develop your expert knowledge of Software Engineering best practices, Software development life cycle including coding standards, code reviews, source control management, build processes, testing, and operations.

You have:

  • Strong understanding of the DOM, HTML5, CSS3 and JavaScript (ES5 & ES6)
  • Experience with jQuery
  • Strong understanding of debugging Javascript code
  • Experience with Responsive Web Design (RWD) patterns
  • Proven ability to create working prototypes (proof of concepts) at varying degrees of fidelity using HTML, CSS, and JavaScript
  • Agile environment using Git and Github
  • Experience building and maintaining a reusable components library

Nice to Have, But Not Required:

  • Experience with TypeScript, RxJS, PWA or other Reactive programming techniques/libraries
  • WebSockets and LocalStorage experience
  • CI/CD skills


Today, more than 20 million people around the world buy through our stores. We celebrate the diversity of our customer base, and we want our employees to reflect those differences. At Scalefast, we’re committed to equal employment opportunity regardless of race, colour, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender, gender identity or expression, or veteran status. We strive to be a more equal opportunity workplace.