Full-Stack JavaScript Engineer at Yopeso | Madrid

Role overview SGS seeks a Senior .NET Full Stack Developer based in Madrid. This role centers on building and enhancing web applications that drive business objectives. The position requires hands-on work across both front-end and back-end, with a focus on delivering reliable, high-performance solutions throughout the software development lifecycle. What you will do Develop and maintain web applications using .NET and related frameworks Collaborate with cross-functional teams to design and implement solutions that meet business needs Improve application performance and uphold code quality standards Participate in all stages of the software development process, from initial planning through deployment Requirements Extensive experience in both front-end and back-end development Strong collaboration skills with both technical and non-technical colleagues Dedication to maintaining high standards in code quality and application performance

Key Responsibilities- Design the architecture of web pages based on provided layouts.- Develop reusable code for future projects.- Implement mobile-first design principles to ensure optimal user experience on smartphones.- Monitor and enhance website performance for speed and scalability.- Exhibit self-management skills and effectively prioritize tasks.Essential Qualifications- Proficiency in Laravel, PHP, MySQL, HTML5, CSS3, JavaScript, Sass, Git, VueJS, and TailwindCSS.- Minimum of 3-5 years of proven experience in PHP Laravel, HTML, CSS, and JavaScript development.- Deep understanding of SCSS and Blade templates (Laravel).- Familiarity with VueJS, AMP, and TailwindCSS is preferred.- Experience in responsive and adaptive design methodologies.- Knowledge of SEO best practices.- Proven experience with collaborative version control systems.- Background in an agile team environment.- Excellent English communication skills, both verbal and written.- Strong grasp of Object-Oriented design principles and methodologies.- Experience with databases, including relational and NoSQL databases.- Competence in integrating third-party APIs and libraries.- Experience with search servers (e.g., Elastic or Algolia) is a plus, but not mandatory.- If you have a GitHub account or have contributed to open-source projects, we'd love to hear about it in your cover letter.

We are seeking a talented Full Stack Developer with expertise in .NET and Angular to join our dynamic team at Sopra Steria. In this role, you will work on diverse projects in the Telco, Energy, and Utilities sectors, contributing to innovative solutions that drive our clients' success.As a Full Stack Developer, you will be responsible for designing, developing, and maintaining web applications, collaborating closely with cross-functional teams to deliver high-quality software solutions.

Role Overview Miratech is hiring a Senior Full Stack Developer in Madrid with expertise in Java and Angular. This position focuses on building and maintaining complex web applications that serve a range of client needs. What You Will Do Design, develop, and maintain web applications using Java and Angular Work closely with cross-functional teams to deliver software solutions Support the full software development lifecycle, from concept through deployment Location Madrid

Groupon, Inc. is seeking an AI Full-Stack Developer to join the team in either Madrid or Prague. The position centers on building and integrating artificial intelligence features throughout the technology stack, helping connect millions of consumers with local businesses around the globe. Key responsibilities Design and implement solutions that incorporate AI technologies into both front-end and back-end systems Collaborate with fellow developers to achieve seamless integration and dependable performance Suggest and develop improvements that enhance user experiences and make business operations more efficient through artificial intelligence Location This role is based in Madrid or Prague.

Role overview psicro seeks a Full-stack Developer in Madrid to support the development of AI-driven software products. This position covers both front-end and back-end responsibilities, contributing throughout the software development lifecycle. What you will do Build and maintain features for AI solutions, handling both client-side and server-side tasks Work closely with colleagues from various backgrounds to deliver dependable software Turn client requirements into scalable, maintainable technical solutions Requirements Background with modern web technologies and frameworks Strong teamwork and clear communication skills Interest in artificial intelligence and its real-world uses This role is located in Madrid.

Role overview SGS is looking for a Java Full-Stack Developer to join the team in Madrid. The position covers both front-end and back-end development, supporting the creation and maintenance of software solutions. Success in this role depends on practical experience and clear communication with colleagues from various areas. What you will do Develop and maintain applications using Java along with modern web technologies Work alongside team members from different disciplines to achieve project objectives Help design, implement, and refine software solutions Requirements Strong experience with Java Proficiency in current web development frameworks and tools Comfort working collaboratively within a team This is an on-site role based in Madrid.

Yopeso brings nearly two decades of experience in software development, building both large-scale systems and tailored products. The company employs more than 300 professionals across five global locations, with a steady focus on growth, transparency, and professionalism throughout each project. Authenticity, curiosity, and ambition shape daily work at Yopeso. Teams operate with trust and integrity, maintaining open communication and a commitment to secure, reliable software. Each project emphasizes high quality and dependable performance. Collaboration plays a central role. Agile teams share knowledge and support one another, working efficiently to deliver software that aligns with the company’s core values and meets real-world needs.

ResilientCo is looking for a Full Stack Engineer in Madrid to help build and improve applications across both front-end and back-end systems. This position involves working closely with colleagues from different areas to deliver projects that support the company's technology goals. Role overview This role focuses on developing features and maintaining systems that serve users and internal teams. Expect to contribute to both user interfaces and server-side logic as part of a collaborative group. Collaboration Full Stack Engineers at ResilientCo participate in team discussions and planning, sharing ideas to improve how applications look and function. Working with designers, product managers, and other engineers is a regular part of the job. Location This position is based in Madrid.

Join the innovative team at thebridge3 as a Lead Instructor for Full Stack Development. In this part-time position, you will play a crucial role in shaping the next generation of developers by delivering engaging and comprehensive instruction in full stack technologies. You will leverage your expertise to create a dynamic learning environment that fosters student success and encourages hands-on experience.

Join Groupon, a leading marketplace where customers explore new experiences and services daily, and where local businesses thrive. We have partnered with over a million merchants worldwide, connecting more than 16 million customers with deals across diverse categories. In a landscape often dominated by e-commerce giants, Groupon stands out as one of the few platforms genuinely committed to propelling local businesses forward based on performance.We are on an exciting journey to radically transform our business through a relentless focus on results. Despite having thousands of employees across multiple continents, we foster a culture that inspires innovation, rewards risk-taking, and celebrates success. Here, your impact can be immediate due to our scale and the rapid pace of our transformation. We blend the best of both worlds: we have the resources and scale of a large company, yet we empower individuals to have significant autonomy and drive meaningful change.About the RoleHybrid from Madrid or ValenciaAs a Full Stack AI Engineer, you will engineer the foundation of our proprietary internal platform that democratizes AI across the organization. This role goes beyond standard full-stack duties; you will construct the framework that enables various teams to develop autonomous AI agents. Your responsibilities will include designing reasoning flows, integration layers, and agent logic that empower AI to execute complex business tasks at scale. This is applied AI engineering: focusing on sophisticated system design and relentless execution rather than model fine-tuning. You will collaborate daily with a newly formed team of engineers and work closely with the AIGO team and cross-functional partners across Global Operations, Customer Satisfaction, and Engineering.

Join causaprima as a Senior Full-Stack Engineer, where your expertise will shape engaging interfaces for our agents. You will develop intuitive dashboards, approval workflows, real-time data visualizations, and a counterparty portal that enhances connectivity across our network.Your ResponsibilitiesReal-Time Communication & Architecture — Implement WebSocket-driven event streaming, agent notification routing, and dynamic query management.Visualizing Financial Forecasts — Create probabilistic cash forecasts with uncertainty bands and detailed insights into invoices and assumptions.Counterparty Portal Development — Build a user-friendly portal for suppliers and customers to track invoice statuses, manage disputes, and view payment commitments securely.Approval Interface Design — Craft a human-in-the-loop interface for reviewing agent reasoning and verifying source documents before action approvals.Session Management & Authentication — Integrate OAuth 2.0 / OIDC, manage JWT with tenant context, and handle session lifecycles with Redis, including magic link token generation for the counterparty portal.API/BFF Layer Development — Develop a TypeScript service layer to mediate between the React frontend and the Python agent backend, securing REST, GraphQL, and WebSocket endpoints.MCP Server Implementation — Establish a Model Context Protocol endpoint for integrating external AI agents, facilitating interoperability across the supply chain.Qualifications5+ years of experience architecting TypeScript/React applications in production environments.Strong systems design skills, with a focus on components, contracts, data flows, and failure modes.Extensive experience in real-time architectures, including WebSockets and event-driven frontends.Proven ability in designing data visualization systems and API layers for multi-tenant SaaS applications.Solid understanding of frontend security practices, including CSP, CSRF, session management, and input sanitization.Proficient in using AI coding tools with strong code review capabilities to ensure secure outputs.Possess a strong product sense, making data-backed recommendations and articulating opinions effectively.

Join our dynamic team at thebridge3 as a Lead Full Stack Instructor. In this pivotal role, you'll be responsible for guiding students through comprehensive full stack development courses, leveraging your expertise to foster a collaborative and innovative learning environment. Our instructors are passionate about technology and committed to equipping the next generation of developers with the skills necessary for success in the tech industry.

Join Our Team:At INFINIT, we are seeking a talented Full Stack Software Engineer to be an integral part of our dynamic product development team. You will play a crucial role in transforming business objectives into tangible, high-quality software solutions.About Us:Founded in 2023, INFINIT is a rapidly expanding fintech scale-up with operations across Europe and the Americas. We are committed to revolutionizing the SME sector through cutting-edge AI technology. Our comprehensive operating system centers around banking, equipping small business owners and their teams with the tools they need to efficiently manage and enhance their operations.By focusing on niche industries, INFINIT provides customized, high-impact solutions while innovating AI-driven products that unlock substantial growth for our clients. Our ambitions are global, aiming to redefine the fintech landscape for SMEs worldwide.Embark on the INFINIT journey as we reshape the SME economy and create meaningful change through innovation!

Join our innovative team at Inetum as a Revit API .NET Developer (Dynamo). We are seeking a passionate developer who is proficient in .NET programming and has experience with the Revit API, specifically utilizing Dynamo for automating workflows and enhancing design processes. This is an exciting opportunity to work on cutting-edge projects in the architectural and engineering sectors.

Join inetum2 as a Software Developer specializing in .NET technologies. This is an exciting opportunity for individuals looking to kickstart their careers in software development. You will work in a dynamic environment, collaborating with experienced professionals to build innovative software solutions.

JetBrains is hiring a Product Designer to focus on the .NET ecosystem. This position involves designing developer tools that improve workflow and make daily tasks more enjoyable. The role is open to candidates in Belgrade, Berlin, Limassol, Madrid, Munich, Prague, Warsaw, Yerevan, or remote within Germany. What you will do Collaborate with engineers, product managers, and fellow designers to build user-centered solutions for .NET products. Shape the visual and interactive aspects of developer tools, ensuring usability aligns with technical needs. Turn research findings and user feedback into clear, effective design concepts. About JetBrains JetBrains creates intelligent software tools used by millions of developers worldwide. The team emphasizes thoughtful design and practical problem-solving to support the work of software professionals.

neoris is looking for a Backend Software Engineer with a focus on .NET technologies to join the team in Madrid, Spain. This hybrid position involves both in-office and remote work. Role overview This role centers on designing, developing, and maintaining backend systems that support neoris applications. The work involves building reliable services and ensuring performance and scalability. Collaboration Work closely with colleagues from different disciplines to deliver software solutions that align with business objectives. Regular communication with cross-functional teams is part of the job. Location This is a hybrid role based in Madrid, Spain. Some days will be spent in the office, with flexibility for remote work.

Join our dynamic global team as a Software Engineer, where you will play a crucial role in ensuring the quality, development, and implementation of our innovative software products. As part of a diverse technology department, you will collaborate with talented professionals from cities like Barcelona, New York, London, Manchester, Bucharest, and India. If you're eager to contribute to a growing company and make a significant impact, we would love to hear from you!About TransPerfect – TechOps:The TransPerfect TechOps team has been instrumental in our company's success for over a decade, delivering technology and services that have greatly enhanced the experiences of our clients and colleagues. From improving workflows for team members to developing core services that underpin our GlobalLink platform, we strive to create scalable client interfaces that make complex ecosystems accessible to everyone.