Front End Developer at Critical Mass, London, £Contract Rate

The Critical Mass technology team is looking for an inspired, motivated, and experienced Sr. Web Developer to join our team on contract through March. We are an experience design agency with a focus on the customer, which means that multi-discipline collaboration and prototyping are at the heart of our process. We 're using the latest technologies including ES6, pub/sub architecture, and a clean component-based approach to deliver reusable, innovative, and responsive experiences. Web performance & accessibility are also key concerns because of their respective importance to user experience and perception of a premium experience.

Our team culture thrives on a balance of collaboration and focused time which means you won 't be spending your days turning PSDs into HTML or simply pulling tickets off a JIRA queue - rather you 'll be part of the design and prototyping process using data and user research feedback as input. You 'll help balance the team between innovation and pragmatism. Additionally, the team has several remote members so we use screenshares and Slack as to keep communication flowing. We have a lot of fun and hope you 'll join us.

You will:

• Collaborate with Design and UX to prototype user interactions
• Mentor other front-end developers
• Ensure compatibility of code across devices and viewport sizes
• Assess and optimize page performance and WCAG compliance
• Work with delivery team to ensure overall quality of the experience and support this with tests and documentation

You have:

• Strong communication skills with a team-centric approach to discussion and decision making within a distributed team.
• Expertise in JavaScript - specifically ES6, pub/sub architecture, REST APIs and React.js. Experience with Redux and GraphQL is preferred.
• Experience using HTML5 semantic markup, CSS3, and CSS & SVG-based animation on responsive consumer-facing websites.
• Full command of Git, the terminal, continuous deployment and integration, and other modern fundamentals.
• Strong troubleshooting ability and technical analysis skills - web performance optimization included.
• WCAG accessibility experience is preferred.
• Agency experience (preferred).