Senior CRO Developer

Company: Harnham
Apply for the Senior CRO Developer
Location: London
Job Description:

Senior CRO Developer

London – hybrid working 2 to 3 days in office

Salary up to £60,000

This is an opportunity to join a growing digital optimisation agency where experimentation, analytics, and performance are at the core of everything they do. You will play a key role in delivering high impact testing programmes for a diverse client base, with real scope to shape how optimisation is delivered and evolve your career in CRO.

The Role

You will join as a CRO Developer, focused on building and delivering A B tests across multiple client websites.

  • Build, implement, and QA A B tests across a variety of platforms
  • Work closely with analysts, designers, and client stakeholders to deliver optimisation strategies
  • Manage multiple experiments at once in a fast paced environment
  • Ensure code quality and performance across all test implementations
  • Contribute to experimentation best practice and optimisation approaches
  • Option to take on more client facing responsibility or mentoring depending on your interests

Your Skills and Experience

  • Strong commercial experience in CRO development and experimentation
  • Hands on experience with testing platforms such as Optimizely, VWO, AB Tasty, or similar
  • Solid front end development skills with a focus on JavaScript, HTML, and CSS
  • Experience working across multiple stakeholders or clients
  • Ability to manage workloads in a fast paced, delivery focused environment
  • Understanding of experimentation methodologies and test QA processes

What They Offer

  • Salary between £40,000 and £60,000 depending on experience
  • Hybrid working with flexibility on office attendance
  • Clear progression opportunities, including potential to move into lead or management responsibilities
  • Exposure to a variety of tools, clients, and optimisation challenges
  • Supportive and collaborative team environment

How to Apply

If you are interested in this CRO Developer opportunity, please apply with your CV or get in touch to discuss further.

Posted: July 1st, 2026