Frontend Developer at Hirenza, United Kingdom, £300 per day
£300 per day
- Outside Spy
- United Kingdom
- Mar 19, 2026
Contract Description
About The Company
Harnham - Data & Analytics Recruitment is a leading recruitment agency specializing in data-driven roles across various industries. With a strong reputation for connecting top talent with innovative organizations, Harnham prides itself on its deep understanding of analytics, digital marketing, and technology sectors. The company is dedicated to fostering a collaborative and inclusive environment that values continuous learning, professional growth, and excellence. Their extensive network and industry expertise enable them to provide tailored recruitment solutions that meet the unique needs of both clients and candidates, ensuring successful placements that drive business success.
About The Role
This is an exciting freelance opportunity for a Frontend CRO Developer based in London, working in a hybrid environment. The role offers a day rate of £300/day outside IR35, providing flexibility and the chance to contribute significantly to a growing optimisation team. As a key member of the team, you will be responsible for supporting the implementation and configuration of testing tools across multiple client websites. Your technical expertise will be instrumental in building high-quality test variations, designing solutions that align with client goals, and ensuring seamless integration of experimentation platforms. You will work closely with client stakeholders and internal teams to deliver impactful A/B tests that improve website performance and user experience. This role offers the opportunity to work on diverse digital products, fostering innovation and continuous improvement within a collaborative environment that values technical craftsmanship and learning.
Qualifications
The ideal candidate will possess strong front-end development skills, with proficiency in HTML, CSS, and JavaScript. Experience in conversion rate optimization (CRO) experimentation and A/B testing across major testing platforms is essential. A solid understanding of backend technologies and API integrations will be advantageous, enabling effective support for experimentation efforts. Candidates should demonstrate excellent problem-solving skills, meticulous attention to detail, and the ability to translate design concepts into functional test variations. Effective communication skills are vital, as the role involves liaising with both technical teams and client stakeholders. The ability to manage multiple projects simultaneously while maintaining high standards of quality is also required.
Responsibilities
While this is a freelance contract, the role offers competitive day rates and the flexibility of a hybrid working environment. You will have the opportunity to work on diverse projects with leading clients, gaining valuable experience in digital optimization and experimentation. The position provides exposure to cutting-edge testing tools and techniques, fostering professional growth. Additionally, working with a collaborative team that values innovation and continuous learning will enhance your skills and industry knowledge. Harnham promotes a supportive work environment that encourages curiosity, creativity, and excellence, ensuring a fulfilling freelance experience.
Equal Opportunity
Harnham is committed to creating a diverse and inclusive workplace. They believe in equal opportunity employment and welcome applications from individuals of all backgrounds, regardless of race, gender, age, disability, or other protected characteristics. The company values diversity and strives to foster an environment where everyone can thrive and contribute to their fullest potential. They are dedicated to promoting fairness and equity throughout their hiring processes and workplace practices.
Harnham - Data & Analytics Recruitment is a leading recruitment agency specializing in data-driven roles across various industries. With a strong reputation for connecting top talent with innovative organizations, Harnham prides itself on its deep understanding of analytics, digital marketing, and technology sectors. The company is dedicated to fostering a collaborative and inclusive environment that values continuous learning, professional growth, and excellence. Their extensive network and industry expertise enable them to provide tailored recruitment solutions that meet the unique needs of both clients and candidates, ensuring successful placements that drive business success.
About The Role
This is an exciting freelance opportunity for a Frontend CRO Developer based in London, working in a hybrid environment. The role offers a day rate of £300/day outside IR35, providing flexibility and the chance to contribute significantly to a growing optimisation team. As a key member of the team, you will be responsible for supporting the implementation and configuration of testing tools across multiple client websites. Your technical expertise will be instrumental in building high-quality test variations, designing solutions that align with client goals, and ensuring seamless integration of experimentation platforms. You will work closely with client stakeholders and internal teams to deliver impactful A/B tests that improve website performance and user experience. This role offers the opportunity to work on diverse digital products, fostering innovation and continuous improvement within a collaborative environment that values technical craftsmanship and learning.
Qualifications
The ideal candidate will possess strong front-end development skills, with proficiency in HTML, CSS, and JavaScript. Experience in conversion rate optimization (CRO) experimentation and A/B testing across major testing platforms is essential. A solid understanding of backend technologies and API integrations will be advantageous, enabling effective support for experimentation efforts. Candidates should demonstrate excellent problem-solving skills, meticulous attention to detail, and the ability to translate design concepts into functional test variations. Effective communication skills are vital, as the role involves liaising with both technical teams and client stakeholders. The ability to manage multiple projects simultaneously while maintaining high standards of quality is also required.
Responsibilities
- Support the onboarding and configuration of testing tools for clients, including site and domain setup considerations.
- Develop high-quality test variations using HTML, CSS, and JavaScript, translating design concepts into live website elements.
- Lead the technical solution design for experiments, ensuring alignment with client requirements and platform capabilities.
- Configure end-to-end tests within A/B testing platforms, including targeting, goal setting, audience segmentation, and analytics integration.
- Follow structured QA processes to verify experiment functionality and performance, completing thorough documentation for each test.
- Collaborate closely with client stakeholders and internal development teams, serving as a key technical contact for experimentation projects.
- Stay updated on the latest CRO trends and testing methodologies to continually enhance experimentation practices.
While this is a freelance contract, the role offers competitive day rates and the flexibility of a hybrid working environment. You will have the opportunity to work on diverse projects with leading clients, gaining valuable experience in digital optimization and experimentation. The position provides exposure to cutting-edge testing tools and techniques, fostering professional growth. Additionally, working with a collaborative team that values innovation and continuous learning will enhance your skills and industry knowledge. Harnham promotes a supportive work environment that encourages curiosity, creativity, and excellence, ensuring a fulfilling freelance experience.
Equal Opportunity
Harnham is committed to creating a diverse and inclusive workplace. They believe in equal opportunity employment and welcome applications from individuals of all backgrounds, regardless of race, gender, age, disability, or other protected characteristics. The company values diversity and strives to foster an environment where everyone can thrive and contribute to their fullest potential. They are dedicated to promoting fairness and equity throughout their hiring processes and workplace practices.
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