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# Senior CRO Developer

- **Company:** Harnham
- **Location:** London, UK
- **Experience:** Expert
- **Salary:** £50,000.0 - £60,000.0
- **Contract:** Permanent contract
- **Skills:** HTML, JavaScript (Programming Language), A/B Testing, Cascading Style Sheets (CSS), Front End Software Development, Optimizely
- **Published:** July 12, 2026
- **Apply:** https://find.jobs/jobs-near-me/apply/ats-redirect/?id=2870828894-2

## About the Role

* Strong commercial experience in CRO development and experimentation
 * Proven front-end development capability with HTML, CSS, and JavaScript
 * Experience working with A/B testing or personalisation platforms such as AB Tasty, Optimizely, VWO, or similar
 * Ability to manage multiple projects and stakeholders across different business areas
 * Experience in agency environments or working across multiple brands or business units
 * Strong problem-solving skills with attention to detail and quality
 * Confident communicator able to explain technical concepts clearly

## Description

* Build, implement, and QA A/B and multivariate tests across client websites
 * Develop high-quality front-end code using HTML, CSS, and JavaScript
 * Work closely with analysts, designers, and strategists to bring test ideas to life
 * Configure experiments within tools such as AB Tasty, Optimizely, VWO, or similar platforms
 * Manage multiple experiments simultaneously in a fast-paced environment
 * Ensure robust QA processes and maintain high technical standards
 * Collaborate with stakeholders across different functions and client teams
 * Contribute to best practices and support continuous improvement within the experimentation function


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