Front-End Developer

We are seeking an analytical and results-driven profile with experience in JavaScript and working with Single Page Applications (SPA). The selected candidate will work closely with our CRO, Data, and UX/UI teams on projects for leading clients across different industries. Implementation of A/B tests using different testing tools (such as VWO, AB Tasty, and Optimizely, among others). Configuration and measurement of A/B tests using testing tools, Google Tag Manager, and Google Analytics. Support in the analysis of test results. Collaboration with internal teams and client stakeholders (Product, UX, Development) to identify and execute testing opportunities. Continuous monitoring and analysis of metrics to improve conversion rates. Technical documentation of implemented developments and solutions.

Solid experience in front-end development with JavaScript. Advanced knowledge and experience working with Single Page Applications (SPA). Experience in CRO projects and A/B testing. Ability to work in multidisciplinary environments (CRO, UX/UI, analytics, development). Nice to Have

Knowledge of modern frameworks/libraries such as React, Angular, or Vue. Experience in user experience (UX/UI) improvements. Familiarity with web analytics tools such as Google Analytics, Hotjar, or Clarity. Advanced knowledge of HTML5 and CSS3. Experience with version control systems (Git). Knowledge of the Firebase ecosystem for testing purposes (Remote Config). Ability to document technical work and communicate results clearly.

We offer a fixed salary according to your worth and experience, plus a performance based bonus. Get the most out of your salary with our Flexible Payment Plan (Restaurant Ticket, Transportation Ticket, Day Care Ticket, and Medical Insurance). Do you know someone that fits in Making Science? Refer him or her, and you can get a bonus if they're hired! Feedback is part of our day to day lives. We recognize a job well done through a continuous feedback model. The opportunity to meet our international team with our Ambassadors Program. We care about a healthy work-life balance. You can count on having flexible working hours and one day a week where you can work from home. You will never stop learning with us: subsidized training, free language classes, learning capsules, an e-learning platform, and many more. Pack your bags! You'll have 23 vacation days, plus 24th, 31st of December and San Publicito are off, and we have afternoons off on the eve of national holidays. Work comfortably and follow your own style, because we don't have a dress code. We know how to have a good time! Never go hungry with our free daily fruit and our vending machine card! Take a break on our terrace, play foosball, darts, or PlayStation Be a part of a young, adventurous, and professional team, with people you'll grow fond of! False FULL_TIME Organization Making Science Unknown false Place PostalAddress España España España GeoCoordinates CRO Developer 2026-05-30T00:29:08

Making Science is an international digital acceleration company with over 1,200 experts across 15 markets, including Spain, Portugal, Mexico, Colombia, France, Italy, the UK, Ireland, Sweden, Denmark, Norway, Finland, Germany, Georgia, and the USA. As a proud consulting partner of Local Planet - the world's premier network of independent media agencies - we deliver a suite of digital, technology, and performance marketing services to a global clientele. Our expertise spans digital marketing and MarTech, software and cloud solutions, artificial intelligence, and SaaS, all underscored by a relentless pursuit of innovation. Making Science was ranked 15th in the FT1000: Europe's Fastest-Growing Companies 2023. Committed to making a positive impact, Making Science actively engages in various ESG initiatives. We've joined forces with the Climate Pledge, the United Nations Global Compact, and Pledge1%, dedicating resources and efforts to support non-profit organizations. Through these endeavors, we are committed to driving meaningful change for a brighter, more sustainable future. As part of its commitment to innovation, Making Science offers its clients end-to-end capabilities required for consulting, development, integration, and maintenance of advanced IT solutions. Our global network of delivery hubs not only fosters job growth but also serves as an incubator for cultivating top-tier tech talent, fueling projects that accelerate transformation and modernisation. Our team is composed of digital native professionals, who have a wide knowledge in the different stages and disciplines of the digital transformation: Digital Strategy, Infrastructures, Software Development, Creativity and UX/UI Design, Digital Marketing, and Big Data. Making Science is People Centric, and we actively bet on our employees! We believe that they are the key to any successful business, and therefore, our greatest asset. We strive to provide daily learning opportunities for those who work with us and their colleagues. It is also really important that they enjoy what they do, and have positive experiences. We want our employees to feel proud of their accomplishments, and that they belong to a company that is in constant growth, because each person's contribution is essential to achieve our success. We believe in the power of diversity and the value of inclusion. At Making Science, our unique experiences, backgrounds, and perspectives are what drive our innovation and success. We are dedicated to providing an equitable hiring process and an inclusive work environment where all individuals are respected and feel they belong. Join us and bring your whole self to work! At Making Science, we are looking to permanently join our team a Front-End Developer focused on Conversion Rate Optimization (CRO) projects, both in web and app environments.