Senior Front-end React.Js

Barcelona, Full time

Who we are:


Marfeel is a publishing platform that that revolutionizes the way publishers create, optimize and monetize mobile websites. Over 850 publishers, including USAToday, Euronews, and El Confidencial use Marfeel to serve a billion mobile sessions, every month. 

We take a Technology-First approach and have a commitment to developing new tools for digital publishers to reach their audience. Our innovative technology, including PWAs, SEO and engagement tools, monetization and experimentation makes us proud of what we can offer to our clients: faster speeds, greater performance, and worldwide distribution.

Our team now has more than 185 members, made up of over 30 different nationalities. With headquarters in Barcelona and offices in New York and Bogotá, our people and our diversity are the reason behind our world-class product, and we’re still growing.

ESLint, Styled Components and Storybook Sponsor

We are looking for a Senior Frontend Engineer to join our Engineering department of over 90 talented developers, and become part of a Core Product team that is responsible for the architecture and the performance of our frontend ecosystem. We obsess about performance and the quality of our code, and we are looking for like-minded developers to join us.


This is what you will do:

  • Deliver work on-time, accurately and most importantly in a robust way that doesn’t degrade the quality of the code base

  • Drive improvements in performance and architecture of the current Marfeel platform

  • Help us become a “Developer’s platform”. This means having extremely smooth and productive developer experience that attracts external developers to collaborate with us


What we are looking for:

  • 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 experience with developing progressive web applications, service workers, push notifications with React and other modern Javascript frontend technologies

  • 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


We will be further impressed if:

  • You have experience with various AWS services and understand the challenges of deploying large applications in the cloud

  • You are an active contributor to a frontend community

  • You have worked with Jenkins and familiar with CI and CD release cycles

  • You have experience with backend languages and frameworks such as NodeJS, Java, Python or any others

  • You are familiar with #perfMatters, Vue, Google Analytics, AdServing, Linters


This will be you as part of the Marfeel team:

  • Open-space, light-filled and eco-conscious office with large sunny terrace
  • Unlimited refreshments including coffee, tea & soft drinks
  • Subsidized healthy & tasty lunch delivered to the office & free fresh fruit 
  • Ping-pong, video games, table football and other games for down-time
  • Free language and yoga classes at the office
  • Subsidized monthly plan to a huge network of health & wellness centres (Andjoy)
  • Transport, restaurant & kindergarten tickets
  • Subsidized health insurance for you and your partner/family
  • Flexible working hours and early finish on Fridays
  • Loyalty sabbatical and vacation days
  • Access to training platforms, courses & materials
  • Referral bonus for talent brought to us by you
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