Senior/Principal JavaScript Engineer

Date posted:

Contract: Full-time

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twentysix is a leading digital agency that develops digital platforms and marketing that drives business change and performance. Connected by data, insight and strategy, we specialise in user experience (UX), development and performance marketing.

We have over 150 digital specialists working with us across Leeds and London, and our clients include the likes of Arla, P&G, Fortnum & Mason and Corinthia Hotels, to name a few.

We’re looking for a Senior/Principal JavaScript Engineer to provide technical direction and make architectural decisions regarding JavaScript and surrounding frameworks for the development team. As well as strong Front-End skills and overseeing end to end project delivery, we are looking for someone to take responsibility for road mapping the future of JavaScript within twentysix.

Based in our Leeds city centre office, which offers an inspiring state of the art working environment and facilities, along with support and focused learning and development opportunities surrounded by experienced digital experts, you can build and excel within your career. 

Due to Covid-19 we are all working remotely, however when the office is open for those that want to work onsite, you can do, or you can do a combination of both. Work equipment such as laptops will be provided.


  • Define and maintain the use of JavaScript within the agency focusing on what technologies we should be using, how we implement these technologies within our current stack and department, and roadmap areas for development
  • To identify future developments, methodologies, and new libraries which we may wish to integrate into our stack
  • Define best practices for integrating and developing within a framework with key considerations given to performance, linting and code structure
  • Sell JavaScript, frameworks, methodologies and approaches within the agency
  • Develop specifications and designs for complex applications or modifying/maintaining complex existing applications
  • Integrate testing automation within JavaScript for continued improvement and monitoring
  • Provide recommendations on platforms and services on client solutions
  • Be a key contributor when it comes to defining API structures
  • Contribute to the research and review of the platforms and services the agency offers, providing recommendations and guidance
  • Assist in the creation of functional and technical specifications ensuring requirements are appropriate, captured and documented sufficiently
  • Be responsible for defining and overseeing the delivery of effective technical workshops and technical requirements gathering activities
  • Oversee technical project delivery to ensure solutions meet their goals and objectives
  • Ensure team practices and principles are followed and work is carried out efficiently and to the highest of quality
  • Hands on with code, including HTML and CSS


  • A proven record of JavaScript experience
  • 7+ years of professional experience in a related role or technology stack
  • Extensive coding experience with strong Front-End skills (CSS, HTML, accessibility and performance)
  • Experience of the modern JAMstack approach including server side rendered techniques
  • Experience in agile and lean delivery methodologies
  • A strong understanding of modern JavaScript (ES6+)
  • Knowledge of existing frameworks with real life experience
  • Ability to define and drive engineering and architectural best practices
  • Knowledge of node.js along with build tools such as Webpack and Gulp
  • Ability to work collaboratively and under pressure


  • Competitive salary.
  • Flexi-time
  • Career development
  • Outstanding private healthcare package for you and your family
  • Enhanced holidays
  • Employee assistance programme
  • Perkbox
  • Quarterly staff benefits
  • Friday sweets, beer and snacks
  • Social events a-plenty
  • £1000 direct application bonus* (when quoting code DAF20/21).

*By applying direct you will qualify for a bonus of up to £1000 (dependent on level of position) when you pass your probation. To qualify for this, you must include the code DAF20/21 in your covering letter.

We welcome applications from previous candidates and pride ourselves of on our values with equality at the core. We do this by hiring and developing a diverse mix of talented people that contribute to our success. Creating a culture of equality isn’t just the right thing to do, it’s also the smart thing. Diverse companies are more innovative and better positioned to succeed. We strive to create a workplace where everyone feels empowered to bring their full, authentic selves to work.

If you require any of this information or an application form in an alternative format, or you would simply like to discuss the role, please contact our Talent Acquisition Manager megan.wilford@twentysixdigital.com

Follow #lifeattwentysix for an insight into working here.

Polite notice to recruitment professionals

Please do not contact us regarding this role. While we respect that many companies do need recruitment agencies, we do not at the moment, and we are happiest recruiting for ourselves. Any resume submitted to us before any agreement with us will be deemed the sole property of twentysix, and in the event of a candidate being hired outside of an agreement, no fee or payment of any kind will be paid.