Front- End Developer

Reports into: Head of Development

Contract Type: Full Time, working 7.5 hours per day, 5 days per week

Location: Hybrid, working 3 days a week in our offices based in Old Street, London

About Us

Nothing is clearer to us than the belief that every woman should include strength training in her life to enhance both physical and mental well-being. It's about building strong bodies and even stronger minds, asserting their right to take up space in the gym, and allowing the spotlight to shine bright on their progress.

To us, strength training represents a determined, goal-oriented mindset and an unwavering work ethic. We don't wait for success; we create it through hard work and determination. When faced with challenges, we don't back down; instead, we break through barriers, recognising that true progress lies on the other side.

These are the pillars that form the foundation of Oner Active. We consistently challenge ourselves to create innovative and impactful products, so that you can perform better. With our range of products and innovative approach, we provide a wide variety of colours to ensure that all skin tones genuinely radiate in Oner.

Our Purpose and Mission

We are on a mission to unite and empower women to be the strongest version of themselves through strength training. We want to inspire women to take centre stage in the gym by promoting strength training, which underpins all movement and sport, as a healthy foundation in life.

Our Benefits

• 25 days annual leave + bank holidays, plus the freedom to work from anywhere for up to 4 weeks a year
• 5% employer pension match through our salary sacrifice scheme
• Generous Oner Active discount and regular office sample sales
• Free Evolve You subscription, on us
• Private Healthcare with Vitality, including optical and dental cover
• Monthly wellness allowance and team workout classes to keep you moving
• Annual discretionary bonus scheme
• Family-friendly maternity & paternity policies that actually support you
• Start-up culture - the chance to learn and make a real impact, backed by hands-on management and career mentoring
• Great employee events like our Summer party, Christmas party and team away days
• Healthy office snacks, fresh fruit and a coffee and matcha bar (plus a chocolate cupboard for a sweet treat for the balance)
• Dog-friendly office

We are looking for a talented Front-End Developer to join our growing in-house Development Team and help build, optimise, and maintain our Shopify Plus estate.

Reporting into the Head of Development, you will be hands-on from day one: turning designs into fast, responsive, and polished storefronts, supporting our busy trading and collection-launch calendar, and helping raise the quality bar across seven stores. This is a genuinely creative role for someone with a real passion for design, animation, and craft on the web. You will write exceptional code, but you will also contribute ideas on how to build best-in-class, high-performing shopping experiences.

You will work closely with the Head of Development, the Digital Trade team, and wider Marketing and E-commerce teams to bring campaigns and collections to life. As one of the early members of the team, you will have room to grow, exposure to new technologies, and the chance to help shape how the team works as it scales.

You’ll Be Responsible For

• Developing and customising Shopify themes to create compelling, responsive, and slick storefront experiences across our Shopify Plus estate.
• Translating designs into functional, pixel-accurate user interfaces, ensuring cross-browser compatibility and mobile responsiveness, with clean and efficient code that is reusable and maintainable.
• Supporting the delivery of our collection launches and trading calendar, building and updating on-site content, campaigns, and landing pages to a high standard and on time.
• Reacting quickly to trading and merchandising needs, implementing same-day updates where required.
• Optimising front-end performance with a strong focus on Core Web Vitals, page speed, and scalability.
• Implementing SEO best practices to support traffic and engagement.
• Collaborating with the Head of Development and other developers to enhance site functionality, following agreed code standards and review processes.
• Helping to build and maintain reusable components and patterns that make future launches faster and more consistent.
• Continuously improving the storefront, contributing ideas and implementing new features based on user feedback, trading performance, and industry trends.

• Rock-solid HTML and CSS/SASS, proven JavaScript experience, and working knowledge of Tailwind CSS.
• Experience with Shopify and the Liquid templating language
• A strong understanding of when to use Liquid's native server-side rendering versus client-side JavaScript, and how each affects performance.
• Familiarity with Shopify's Online Store 2.0 development architecture.
• Experience with responsive and adaptive design, ensuring a seamless experience across all devices.
• Experience with web animation (CSS transitions and SVG animation; GSAP and/or Anime.js a strong plus).
• A solid understanding of SEO principles and how to build in line with them.
• Excellent problem-solving skills and strong attention to detail.
• Strong communication and team collaboration skills.

• Experience with, or a clear understanding of, headless/composable commerce architectures and the considerations involved in transitioning to one.
• Experience mentoring, leading, or line-managing developers, whether formally or as a senior individual contributor.
• Familiarity with modern front-end frameworks such as React or Vue.js.
• Experience with data migration or re-platforming tools and projects.
• Experience working within premium, luxury, or fashion brands.
• Familiarity with Git and modern version control workflows.

At Oner Active it’s about embracing diversity and empowering every individual to reach their full potential. We are committed to creating an environment where everyone feels valued, supported, and able to thrive.

We welcome applications from all backgrounds and are dedicated to ensuring that everyone has equal access to opportunities during the recruitment process. If you require any reasonable adjustments or additional support, we encourage you to reach out to our Recruitment team — we’re here to support you every step of the way.

We are an activewear brand created by women, for women. Women who strength train, women who love to move. Women who take up space – physically, mentally, unapologetically. Because we believe every woman deserves to feel strong in her mind, body and spirit – and look amazing in the process!