.About usSmile is the European leader in open source digital services, combining innovation, technology, and a passion for digital transformation. With nearly 2,000 employees across the globe, we deliver hundreds of strategic digital projects annually for some of the biggest names in the industry. Our expertise spans Digital, Business Apps, Embedded & IoT, and Infrastructure. As part of our team, you will have the opportunity to work on cutting-edge projects, leveraging our extensive knowledge and commitment to open source solutions to drive digital innovation.Our team is expanding, and we're looking for a freelance Senior FrontEnd Engineer to join us on a long-term project for a prestigious client based in Barcelona. This role is ideal for someone who is passionate about front-end development and digital innovation, looking to make a significant impact in a dynamic environment.Role overviewAs a Senior FrontEnd Engineer at Smile, your primary mission is to spearhead the development and maintenance of front-end solutions directly within our clients' environments. This role is pivotal in ensuring that our digital solutions meet the highest standards of innovation, usability, and performance.- Collaborate closely with clients to understand their front-end development needs and deliver high-quality solutions.- Lead the development, optimization, and maintenance of web applications with a focus on user experience and performance.- Implement responsive design principles to ensure our applications are mobile-friendly.- Utilize modern JavaScript frameworks (React, Angular, Vue.Js) to build dynamic and interactive user interfaces.- Conduct unit testing and integrate test automation frameworks to ensure reliability and efficiency of code.- Participate in the personalization of user experiences through AB testing and similar methodologies.- Ensure adherence to best coding practices and standards for front-end development.Required skills and experience- Demonstrated expertise in optimizing front-end performance.- Proficient in unit testing and test automation, with experience in relevant tools, frameworks, and libraries.- Knowledge in personalization techniques, including AB Testing, with experience in Adobe Target and Google Optimize.- Hands-on experience with Google Tag Manager, Storybook, Chromatic, BitBucket, and Git.- Advanced proficiency in SASS/SCSS and JavaScript frameworks such as React, Angular, and Vue.Js.- Proven track record in implementing mobile-first, responsive web designs.- Experience with Akamai or similar CDN technologies.Your ProfileYou have an advanced degree in computer science or a related field, complemented by at least five years of professional experience in frontend development. This includes expertise in specific frameworks and technologies relevant to the frontend domain, such as React, Vue.Js, Angular, and proficiency in CSS preprocessors like SASS or SCSS