Senior Front-end Developer - React

Publishing, media, mobile, advertisement, technology, Barcelona, start-up: all-in-one!

Job details

  • Full-time
  • map markerBarcelona, ES
  • globeRelocation paid
  • cardRequires Work Permit
    Requires that you're a citizen or have a valid work permit / visa sponsorship to work in the country in which this position is based.
  • routeSenior
  • routeRequired language: English
  • Front-end Developer
  • tagMust Have: ReactOther Required: JavaScript, WebpackNice to Have: Amazon Web Services, Backend Development, Google Analytics

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We are Marfeel, one of the hottest European start-up companies, and we help publishers of all sizes to create, optimize and monetize their mobile websites. We have been named 16th fastest-growing European company of 2018, by The Financial Times, but we still think we have a long way to go to where we want to be.

We are looking for a Senior Frontend Engineer to join our Engineering department of over 70 talented developers, and become part of a Core Product team that is responsible for the architecture and the performance of our frontend ecosystem that supports over 700 million visits monthly. We obsess about performance and the quality of our code, and we are looking for like-minded developers to join us.

Our headquarters are based in sunny Barcelona and our office has a huge terrace to enjoy! 

As a Senior Front-end Developer at Marfeel you will:

  • Deliver work on-time, accurately and most importantly in a robust way that doesn’t degrade the quality of the codebase
  • Drive improvements in performance and architecture of the current Marfeel platform
  • Help us become a “Developer’s platform”. This means having an extremely smooth and productive developer experience that attracts external developers to collaborate with us
  • Join a fun and dynamic Core product team that follows Agile practices
  • Have the opportunity and support to grow and develop your career further
  • Be able to help us shape our rapidly growing Engineering department
  • Be part of a multicultural and talented company, consisting of 30 nationalities

If this sounds interesting and you are up for the challenge, sit down and let us introduce Marfeel to you:

Main requirements

  • At least 5 years of experience building software that works at web scale
  • You have experience with developing progressive web applications, service workers, push notifications with React and other modern JavaScript Front-end technologies
  • You have a solid understanding of the web technology stack (i.e. headers, cookies, cross-domain restrictions, HTTPS, caching, optimization opportunities, hardware acceleration, junk and scroll performance, server-side rendering etc.)
  • You have worked with Styled Components and Style Sheet Languages, and you understand their tradeoffs
  • You know how to get the most out of Babel and Webpack for the performance gains
  • You actively seek out performance improvements in loading times, interaction smoothness, scroll jankiness and reactiveness (i.e.: infinite scroll, swiping, lazy load, JS throttling, etc.)
  • You take ownership of your own and your team's code quality. Writing tests is second nature to you, and you have a broad understanding of UI testing technique
  • You help develop knowledge and drive process improvements in your team
  • You have experience working in cross-functional collaborative teams, following Agile best practices
  • You have high emotional intelligence and finding it easy to empathise with others

Nice to have

  • You have experience with various AWS services and understand the challenges of deploying large applications in the cloud
  • You have experience with Back-end languages and frameworks such as Node.js, Java, Python or any others
  • Experience with Google Analytics and ADServing
  • You are familiar with #perfMatters
  • You have experience with Vue.js and Linters
  • You are an active contributor to a Front-end community
  • You have worked with Jenkins and familiar with CI and CD release cycles


  • Talented, international and multicultural team (more than 30 nationalities and more than 8 languages). You will not get lost in translation
  • Flexible working hours
  • Free coffee, tea, juices and soft drinks
  • Sunny office terrace
  • Ping-pong, Mario Kart and foosball tournaments
  • Nerf guns
  • Free language and yoga classes
  • Team building events
  • Training, books and all you need to feel the empowerment
  • Beach: 30 minutes walking
  • Transport, restaurant and kindergarten tickets
  • And, Referral Bonus if you bring other talented people like you

Apply now

Sign up to apply

Or sign up to refer and earn a reward of €300