Senior Front End Developer


Reports to: Lead Frontend Developer

Employment Status: Full time

Location: City Center of Poznan – Poland

Company Overview

Do you subscribe to Netflix or ever purchase a live sporting event on Pay-Per-View? If so, you have a high chance of knowing already what Cleeng does.

Each month, nearly 2 million viewers from more than 100 countries in the world access a video platform secured by Cleeng. We work with sports federations, TV networks, broadcasters, and media companies to deliver an efficient, tailored, premium video experience. With our e-commerce heritage and market-leading video business solutions, highly motivated team of 50 people in Amsterdam (HQ), NYC, Poznan, Sydney and Manila, and good funding, Cleeng is quickly becoming the indisputable leader in this space.

Working at Cleeng is rewarding, fun, and challenging. We thrive on innovation. If you want to join a fast growing business, and make a real contribution, come join our team and help shape the future of video consumption.

Your impact & mission

Within our R&D centre, your mission is to ensure our front-end looks innovative & awesome across devices, and uses an optimal code structure.


  • Implementing and designing architecture for new features and also refactoring existing code and solutions
  • Optimizing applications for maximum speed, scalability and availability
  • Understanding the business side of projects and being able to find the best balance between  business and the technical aspects
  • Supporting/mentoring developers and other project members
  • Work with Designers, Product Managers and Engineers to grow concepts through interactive design exploration, ideation and user validation;
  • Understand the different touch-points our clients and customers go through: Dashboard, Check-out, Website, Apps, and come up with practical ideas to bring them to the next level;
  • Relentlessly think how to optimize user experience, and drive two important KPIs of eCommerce: high conversion rates and low support inquiries;
  • Ultimately, you develop the front-end elements that make us be the leader of the video ecommerce industry.

Required Skills/Experience:

  • Excellent knowledge of pure JavaScript and one of leading framework (React / Angular)
  • Very good knowledge of HTML5, CSS3/SASS/LESS, BEM and RWD with ease
  • Very good knowledge of tools using during the front-end development (Webpack, Gulp, Node.js)
  • Keeping well organized data-flow and state of application (good knowledge one of redux/MobX/flow or other)
  • Experience with RESTful API or GraphQL
  • Experience in frontend unit testing
  • Good understanding of Agile software development processes and principles
  • Strong affinity with UX design & best practices on visual design (e.g. material design)
  • High sense of quality achievement: from mockups, to development, testing and optimization;
  • Having worked for at least 3-4 years in a similar position and be able to show what you have achieved;
  • Good communication skills, especially in English

Our tech stack and organization:

  • Front-End is written in React, AngularJS
  • Back-End is in PHP 7 with our own framework based on Zend
  • We use state of the art development environment, including New Relic, AWS, Cloudflare, Invisionapp, pivotal, and hotjar.
  • We love sharing knowledge and improving our skills on internal workshops and trainings.

What we offer: 

  • Our company grows 100%+ every year, so there are many opportunities for talented people.
  • Work with an international team of experts, in Poznan, Philippines, NYC, Amsterdam and Australia. 11 nationalities and counting!
  • Work on Unique, market leading, SaaS products “eCommerce for Videos”, with clients all over the world, from New-Zealand, Japan, Europe, US and Latam;
  • Cooperation with amazing partner ecosystem, working with leaders of the industry: IBM, Brightcove, Livestream, Accedo, Roku, Apple;
  • Good salary package, one that fits your needs.
  • Flexible working hours
  • Work closely with people who love their jobs and get all together to the next level
  • A great, full of energy and brand new space (Cleeng office) in the very middle of the city!

Play the video and get to know us

Is your position not listed?

If you want want to learn how real global online start up works, if you are relaxed but professional, if you are eager to change the world, if you are ready to work hard and bring innovative ideas to the team, then, send us your CV and your motivation to

There are lots of reasons to work here

One talented and passionate team
Join a community of professionals who push each other to strive while enjoying what they do. We like to share knowledge, experience and inspire each other every day. We like to share our knowledge and experience. Be encouraged to share your ideas and perspectives!
Global scale
Diversity defines us. We have offices in The Netherlands, USA, Philippines, Australia, and Poland. Our different backgrounds and over 14 nationalities make our workspace a unique environment and a truly international experience.
Shape tomorrow's product
Don't just watch, participate in the future of premium content consumption. We are thriving in a booming and exciting industry where you could develop your skills.
Who said party?
Relaxed professionals, that’s our motto! Be part of a fun team. Expect dinners and meetups. Join our CS go or chess intercontinental tournaments. Travel the world to work face to face with your colleagues and enjoy the ride!
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