Senior Frontend Engineer at Stack AI | Spain

Join Version 1 as a Senior Full Stack Engineer and play a pivotal role in developing innovative software solutions that drive our business forward. You will collaborate with cross-functional teams to design, implement, and maintain robust applications while leveraging your expertise in both front-end and back-end technologies. If you are passionate about coding, love tackling complex challenges, and are eager to work in a dynamic environment, we want to hear from you!

jobgether is looking for a Senior Full Stack Engineer based in Spain. This role centers on building and maintaining both front-end and back-end systems that support the company’s job search platform. Role overview As a Senior Full Stack Engineer, the focus will be on designing, developing, and supporting applications that deliver a smooth and responsive user experience. The position involves working across the technology stack to ensure applications perform reliably and efficiently. What you will do Design and implement features for both front-end and back-end systems Maintain and improve application performance and responsiveness Work with cross-functional teams to deliver software that meets user needs Requirements Strong background in software development Proficiency in multiple programming languages Solid understanding of web technologies This position supports jobgether’s mission to simplify job searching by delivering reliable and user-friendly software solutions.

About the CompanyJoin a dynamic and innovative SaaS company that is revolutionizing the way leading consulting firms and researchers acquire insights. Our client’s state-of-the-art survey platform empowers users to swiftly craft high-quality surveys, enhance collaboration, and achieve impactful results—all while avoiding the pitfalls of outdated tools and processes. Trusted by top consultancies worldwide, they are on a mission to expand their team to develop high-value features and improve code quality.The RoleOur client is in search of a Senior Full-Stack Engineer to become a pivotal member of a small yet highly skilled engineering team. The ideal candidate is a versatile generalist with extensive expertise in TypeScript, who flourishes in an environment characterized by autonomy and minimal meetings. You will be instrumental in both developing new products and enhancing a solid existing codebase, with a focus on maintaining engineering excellence and clean coding practices.What You’ll Do Innovate and implement new features across the entire stack (frontend + backend). Work collaboratively with senior engineers, product managers, and leadership. Engage in a thorough code review process that emphasizes quality and maintainability. Take ownership of projects from conception to deployment in a remote-first, asynchronous work environment.

Join Version 1 as a Senior Full Stack Engineer and be part of a dynamic team that is dedicated to delivering innovative digital solutions. You will play a crucial role in the development of full-stack applications, utilizing the latest technologies in the digital, data, and cloud sectors. Your expertise will contribute to crafting scalable solutions that meet client needs.

Jobgether is looking for a Senior Full-Stack Engineer with strong experience in Python and React. This position is based in Spain and centers on building and maintaining web applications that improve how users interact with our platform. What you will do Design, develop, and maintain web applications using Python and React Work closely with team members to deliver features that enhance the user experience Contribute to technical decisions and help set the direction for ongoing projects Mentor junior developers and support their growth Requirements Strong knowledge of both front-end and back-end development Proficiency in Python and React Experience working in an agile team setting Ability to collaborate effectively and communicate technical concepts clearly

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.

N-iX is seeking a Senior Full-Stack Engineer (Spanish-speaking) to enhance our dynamic team.Our client stands as one of the foremost global fashion retailers, operating across more than 200 markets through a blend of e-commerce platforms and thousands of physical stores worldwide. This company expertly manages the entire fashion value chain—from design and manufacturing to distribution and retail—emphasizing flexibility, digital integration, and sustainability.Technology is pivotal in all facets of the business, including stores, e-commerce, logistics, and supply chain. Our engineering teams operate in small, autonomous product teams, taking full ownership of the solutions they develop. Engineers are encouraged to grasp the broader business context, engage directly with stakeholders and users, and play an active role in technical and product decisions.

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 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.

Veeva Systems is a purpose-driven leader in the cloud industry, dedicated to expediting the delivery of therapies to patients in the life sciences sector. As one of the fastest-growing SaaS companies globally, we've achieved over $2 billion in revenue last fiscal year, with substantial growth opportunities on the horizon.Our core values are integral to our success: Do the Right Thing, Customer Success, Employee Success, and Speed. In 2021, we made history by becoming a public benefit corporation (PBC), which legally mandates us to balance the interests of our customers, employees, society, and investors.As a Work Anywhere organization, we offer flexibility to work from home or in the office, enabling you to thrive in your preferred environment.Join us to transform the life sciences sector, as we are committed to making a meaningful impact on our customers, employees, and communities.The RoleAt Veeva Link, we are developing the intelligence layer for life sciences by crafting connected data applications that accelerate drug development and enhance patient outcomes. Our belief is simple: the combination of high-quality data and cutting-edge software provides immense value.Execution is paramount. We prioritize speed, accuracy, and quality in our daily work. Our engineering approach focuses on clear product definitions leading to precise technical designs, leveraging a modern tech stack to deliver dependable applications with an excellent user experience.Our initiatives focus on two primary areas:Data-Driven InsightsWe create sophisticated applications that map and analyze global scientific and medical expertise, delivering impactful insights and AI-driven intelligence. Our engineers tackle complex data modeling, entity resolution, and advanced machine learning challenges.Intelligent Business Workflows

About Us:At Wizeline, we are a premier global technology solutions provider specializing in AI-native digital products and platforms. Our mission is to empower organizations by harnessing data and AI to expedite their market presence and transform their operations. We pride ourselves on fostering an innovative culture that emphasizes growth, collaboration, and impact.With the right talent and innovative ideas, the possibilities are endless.Are You the Right Fit?If this sounds exciting, let’s see if you align with the following:

Ebury empowers ambitious businesses to achieve global growth, and we apply the same philosophy towards our team members. We promote innovation, collaboration, and problem-solving within a culture that values belonging, support, and empowerment for everyone to succeed.If you are a collaborative individual eager to revolutionize business operations globally, we invite you to connect with us. Let's discuss how Ebury can elevate your career and help you shape the future.Senior Full-Stack Developer - FintechMálaga Office - Hybrid: 4 days in the office, 1 day remoteBecome a part of our Technology Team at Ebury’s Málaga Office.Impact-Driven Senior Full-Stack Developer Needed: Shape the Future of Our Client Platform with Your ExpertiseAre you passionate about fostering growth in the digital financial ecosystem? Do you thrive in a culture where you can take full ownership of product development and focus on results? Elevate our client trading and payments platform as a Senior Full-Stack Developer and deliver top-notch solutions to our global clients alongside our vibrant teams in South America and Europe.We seek individuals with the right attitude, a strong work ethic, and an entrepreneurial spirit who are willing to tackle challenging questions. You should be guided by data while being driven to solve customer issues. A natural curiosity and a commitment to continuous learning are essential. You should be proficient in various programming languages, frameworks, and tools, with well-informed opinions on the best solutions to address our most significant challenges.Why Join Ebury?Looking to thrive in a high-growth environment? We are in a constant state of expansion. Do you aspire to create a better world? We advocate for inclusion and stand firm against all forms of discrimination. We have zero tolerance for intolerance and celebrate the diversity that contributes to our success as a modern organization.At Ebury, you will find an internal group dedicated to discussing how to promote a diverse and inclusive workplace for all members of the Technology Team. If you’re excited about this job opportunity but feel your background doesn’t perfectly align with the job description, we encourage you to apply anyway. You might be the ideal candidate for this or other positions we have available.Prepare to Elevate Your Career:In our Tech team, your professional growth is paramount. Thanks to our career development programs, you will have the opportunity to advance your skills and expertise.

About the Role Talan is looking for a Senior Full Stack Developer in Málaga. This position works across both front-end and back-end technologies to design and build applications that improve user experience and support business goals. What You Will Do Develop and maintain web applications from concept through deployment Collaborate with team members to deliver high-quality solutions Apply experience in both front-end and back-end development to solve complex problems Contribute to technical decisions and share knowledge with colleagues Location This role is based in Málaga.

N26 is looking for a Senior Full-Stack Security Automation Engineer to join the Security Engineering team in Barcelona. This team builds and scales the N26 Security Platform, developing internal products and automation systems that support specialized teams across the company. The work directly affects the security of millions of users. This position offers autonomy and the chance to solve complex technical problems. Senior engineers here lead technical decisions and translate detailed security requirements into scalable software. The focus includes GenAI and LLM initiatives, where the role involves building core architecture to safeguard sensitive data and improve data governance. Responsibilities extend beyond assessing AI-related risks to designing and implementing mitigation strategies. The scope covers enhancing secure-by-design features throughout the technology stack, supporting the resilience of the N26 ecosystem. By delivering solutions for Product Security Programs, this engineer helps teams ship secure code more quickly. What you will do Design and own end-to-end solutions: Lead the architecture and implementation of full-stack features, including backend services and internal dashboards. Build the security platform: Develop tools and platforms that enable security teams to automate threat detection, incident response, and vulnerability management at scale. Enable the organization: Work with teams across the security department to create shared infrastructure and automation for efficient operations. Drive technical excellence: Select appropriate tools and maintain high standards for code quality, automated testing, and system reliability.

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.

About UsAt Constructor, we are pioneering a next-generation platform designed to enhance search and discovery in the ecommerce sector. Our innovative search engine, crafted entirely in-house, utilizes transformers and generative LLMs to optimize critical metrics such as revenue, conversion rates, and profit. With a commitment to excellence, our engineering team has developed a proprietary engine that consistently outperforms competitors in A/B testing, and we strive to maintain this leadership by continuously pushing the boundaries of AI technology.Our engine is built for extreme scalability, processing over 1 billion queries daily across 150 languages and serving approximately 100 countries. Esteemed ecommerce brands like Sephora, Under Armour, and Petco rely on our technology to enhance their operations.We are a passionate team dedicated to problem-solving and improving the experiences of our customers and colleagues. Our core values include empathy, openness, curiosity, and a commitment to continuous improvement, as we believe that empowering individuals within the company leads to remarkable outcomes.Founded in 2019 by Eli Finkelshteyn and Dan McCormick, Constructor is a U.S.-based company driving innovation in ecommerce.About the TeamThe Retail Media team is focused on creating a platform that bridges ecommerce retailers and brands. This innovative retail media product allows brands to purchase placements within our customers' search, browse, recommendations, collections, or quizzes results. Our comprehensive platform seamlessly integrates with online retailers, offering advanced targeting, bidding, and analytics capabilities to enhance ad visibility and optimize performance. We are a collaborative group of engineers passionate about overcoming challenges and dedicated to enhancing lives through technology.As a member of this new team, you will play a crucial role in developing a user-friendly Customer Dashboard interface that supports both retailers and brands.About the JobYour primary responsibility will be to design, implement, and maintain a web application while closely collaborating with fellow engineers.Work alongside Product and Design teams to develop Retail Media functionalities.Collaborate with both technical and non-technical partners to enhance existing functionalities.Engage with stakeholders within and outside the team.Deliver features for the Customer Dashboard using Typescript and React, while integrating with backend services developed in Python.

At Affirm, we are on a mission to transform credit into a more transparent and customer-friendly experience. We empower consumers with the flexibility to buy now and pay later without any hidden fees or compounding interest.Join our Acquisition & Onboarding team as a Staff Full Stack Software Engineer within the Consumer organization. This pivotal leadership role is ideal for an engineer who can establish technical direction, influence architectural decisions, and enhance the quality and speed of full stack development across mobile, web, and backend systems. Your work will lay the foundation for the first interactions our customers have with Affirm, fostering trust, clarity, and value from the outset. As a Staff Engineer, you will design long-term technical strategies, mentor senior engineers, and amplify our team's impact through your technical expertise, operational excellence, and navigational skills in uncertain situations. Collaborate with product, design, and engineering to deliver seamless, high-performance, and accessible user experiences that drive conversion, retention, and business growth.

Role overview Talan is looking for a Senior Full Stack Developer to join the Málaga office. The focus is on designing, building, and maintaining web applications using Node.js and Angular. The goal: deliver features that improve user experience and help achieve business objectives. What you will do Develop and support scalable web applications with Node.js and Angular Collaborate with cross-functional teams to deliver reliable, high-performance solutions Mentor junior developers and help define software development practices Offer technical input and ideas to create solutions that adapt as the business grows Requirements Solid experience building web applications with Node.js and Angular Ability to work with colleagues from a range of disciplines Focus on quality and performance in software development Interest in sharing knowledge and supporting teammates’ growth

Role Overview Miratech is looking for a Senior Full Stack Developer with strong experience in Java and Angular. This position is based in València. What You Will Do Develop web applications using Java and Angular Enhance and maintain existing platforms Collaborate with cross-functional teams to deliver software that meets client requirements