You will be expected to commence work remotely initially. Subsequently, with the anticipated opening of our Barcelona office in late 2024, your presence in the office will be required for three days per week.


A Senior Front-end Developer at FX helps to pioneer and develop innovative frontend products for Connected TV platforms. Utilising their experience and expertise to architect technical solutions, they advise and support the growth of individuals, helping to review the development team's work and sharing knowledge. They work closely with the Heads of Engineering and Technology to scope work and see it through to execution and completion, and are confident enough to suggest solutions to clients when called upon. A Senior Front-end Developer at FX will have 5+ years of experience with JavaScript and be confident in their knowledge to make decisions and drive the direction of development work at FX.


    • Work with both the Head of Engineering and Head of Technology to propose technical solutions to business problems, attending client meetings where required.
    • Contribute to the frontend development of Connected TV applications, making suggestions on architecture and approach in collaboration with the other engineers on the project.
    • Work with the sales and marketing team to propose technical solutions to clients problems
    • Provide inspiration and guidance to help other members of the development team
    • Regularly code review pull requests by the development team, commenting on where improvements can be made and enforcing the appropriate coding standards
    • Advise the Head of Engineering as to the tools and services that could be used to help improve the efficiency of the development team
    • Advise the Head of Technology as to the technology that could be used to help improve the quality of our applications
    • Attend industry events to broaden understanding of development tools and processes
    • Attend training and events to ensure continued self-improvement
    • Maintain a research and development attitude towards work


    • 5+ years of relevant professional experience in the development of complex web applications
    • Expert knowledge in JavaScript
    • Expert knowledge of Git version control and knowledge of Git flow
    • Experience in unit testing using a modern testing library (e.g. Jest)
    • Deep understanding of APIs, including RESTful APIs
    • Deep understanding of web inspection tools, along with web profiling and step debugging
    • Advanced understanding of web architecture, including transfer protocols and the makeup of a browser
    • Confident usage of CLI tools for frontend workflow, including yarn and npm
    • Some understanding of modern CI/CD tooling
    • A willingness and aptitude to change, with a passion to pick up new tools and processes
    • Effective time-management skills
    • Proficiency in English, both written and spoken.


      • A bachelor's degree (or equivalent) in Computer Science or related scientific field, e.g. Mathematics, Physics, or demonstrable knowledge in Computer Science if self-taught
      • Experience in implementing players (video and audio) and familiarity with open source players such as hls.js.
      • An understanding of playback technology, including manifest formats, DRM, and subtitles formats.
      • Experience working with Typescript
      • Experience working with WebGL
      • Knowledge of RxJS and streams in JavaScript


      Thanks for taking the time to learn about this role. We just wanted to remind you that even if you think you don’t tick all the boxes in the job description, we encourage you to apply anyway — you could still be a perfect fit! And don’t forget to take a look around on our careers page for other opportunities. We can’t wait to hear from you!