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# CRO Developer

- **Company:** Harnham
- **Location:** Manchester, UK
- **Salary:** £50,000.0 - £60,000.0
- **Contract:** Permanent contract
- **Skills:** HTML, JavaScript (Programming Language), A/B Testing, Cascading Style Sheets (CSS), Software Debugging, Web Analytics, Web Platforms, Build Management, Optimizely
- **Published:** July 22, 2026
- **Apply:** https://www.adzuna.co.uk/jobs/details/5809726401

## About the Role

* Strong commercial experience as a CRO Developer, Front End Developer, or Experimentation Developer
 * Hands-on experience building and deploying experiments using HTML, CSS, and JavaScript
 * Experience with CRO and experimentation platforms such as Optimizely, VWO, AB Tasty, Convert, Dynamic Yield, or similar
 * Strong understanding of A/B testing methodologies and experimentation principles
 * Experience working with web analytics and performance measurement tools
 * Ability to write clean, efficient, and maintainable front-end code
 * Understanding of customer journeys, user behaviour, and conversion optimisation
 * Comfortable working closely with technical and non-technical stakeholders
 * Experience within performance marketing, ecommerce, lead generation, or high traffic digital environments is beneficial

## Description

As a CRO Developer, you will be responsible for building, implementing, and maintaining A/B tests and experiments across a range of digital products. You will work closely with analysts, marketers, designers, and stakeholders to translate hypotheses into live experiments that drive measurable business results.

 * Build and deploy A/B and multivariate tests using HTML, CSS, and JavaScript
 * Develop high-quality experiment code across websites and digital platforms
 * Work with CRO and product stakeholders to turn testing ideas into live experiments
 * Implement personalisation and experimentation campaigns using leading CRO tools
 * Ensure experiments are technically robust, performant, and accurately tracked
 * Debug, troubleshoot, and optimise testing implementations
 * Collaborate with analytics teams to support experiment measurement and reporting
 * Contribute to experimentation best practices, processes, and governance
 * Identify technical opportunities to improve customer journeys and conversion performance


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