CRO Developer - Contract at Harnham, London, £300-£375 per day

CRO Developer (Contract)

Analytics Agency, CRO

London - 1 day per week in office

£300-£375 per day - Outside IR35

This is an opportunity to join a high-performing experimentation team delivering impactful conversion rate optimisation projects across a diverse client base. The team is growing quickly and has already exceeded its annual targets, creating a need for additional contract support on a flexible, part-time basis. You will contribute to a steady pipeline of web experimentation initiatives while working in a fast-paced, collaborative agency environment.

The Company

They are a specialist digital consultancy focused on optimisation, analytics and search. Their work spans three core disciplines, blending experimentation with broader customer experience and performance insights. They partner closely with media and marketing teams to translate on-site behaviour into actionable CRO strategies. The environment is delivery-focused, collaborative, and designed to move quickly when the right expertise is introduced.

The Role and Deliverables

• You will take ownership of front end development for experimentation programmes, supporting business-as-usual test delivery across multiple clients.
• Build and deploy A/B tests across client websites
• Deliver a consistent output of experimentation work, including copy and image variations
• Collaborate with CRO and analytics teams to translate hypotheses into live tests
• Work across a variety of site architectures and front end environments
• Ensure quality and accuracy of tests across browsers and devices
• Support ongoing optimisation activity with reliable, scalable code

Your Skills & Experience

• Strong experience as a front end developer within an agency environment, supporting CRO or experimentation programmes
• Proven experience working with modern JavaScript frameworks such as React and Next.js
• Strong proficiency in JavaScript, HTML and CSS for building and modifying client-side experiences
• Familiarity with experimentation platforms such as AB Tasty, VWO, Optimizely, Webtrends or Convert
• Experience delivering high volumes of front end changes in a structured and efficient way
• Ability to work across different client setups and technical stacks in a fast-paced delivery environment

How to Apply

If you have agency-side front end development experience and are available for a flexible contract, apply now for immediate consideration.