Full Stack Software Engineer at infinit | Madrid

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.

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.

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 Yopeso, a leading software development company with over 20 years of experience in delivering innovative software solutions, ranging from large-scale applications to niche products. Our dynamic team of more than 300 professionals across five locations is deeply committed to cultivating an environment of growth, transparency, and professionalism.At Yopeso, we embrace values such as authenticity, curiosity, and ambition. These principles empower us to forge robust connections within our community and with our partners, ensuring trust, integrity, and transparency in all our endeavors. We continuously challenge ourselves to develop high-quality, high-performance, and secure software solutions that meet the evolving needs of our clients.Our collaborative and agile approach enables passionate professionals to work efficiently in teams, focusing on creating impactful products that resonate with our authentic selves.

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.

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.

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.

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.

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

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.

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

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.

We are seeking a highly skilled Senior AI Operations Engineer to join our innovative team at dlocal. In this pivotal role, you will leverage your expertise in AI and machine learning to enhance our operational processes, ensuring efficiency and effectiveness across our systems. You will collaborate closely with cross-functional teams to implement AI-driven solutions that will optimize our services and improve our overall performance.

Role overview The Senior AI Engineer at zooplusse will design and develop advanced AI models to address business objectives and enhance customer solutions. Collaboration with colleagues from various departments is a key part of this role, supporting the delivery of impactful AI-driven projects. What you will do Develop and improve AI models for practical, real-world use cases Partner with cross-functional teams to implement AI solutions Take the lead on AI initiatives that shape business results and customer experiences Location This role is based in Madrid.

Join Causa Prima as a Senior AI / LLM Agent Engineer, where you will play a pivotal role in shaping our innovative product. You will design, develop, and manage autonomous agents that facilitate various critical business processes, including invoice validation, dispute resolution, inter-company negotiations, and cash flow optimization.Your ResponsibilitiesAgent Architecture — Create a robust multi-agent system focusing on agent boundaries, event contracts, orchestration patterns, and the integration of LLM reasoning with deterministic enforcement.Document Processing Pipeline — Develop a system for the ingestion, classification, and structured extraction of financial documents such as invoices and contracts using LLM-based parsing and vision models.Validation & Anomaly Detection — Implement business rule checks, three-way matching, and pricing discrepancy detection to ensure data integrity and identify anomalies over time.Integration Framework — Design integration solutions connecting with Gmail, Google Drive, Slack, banking APIs, crypto wallets, and accounting platforms, including robust authentication and data normalization processes.Knowledge Graph — Build a Neo4j context graph to capture implicit business knowledge, focusing on entity extraction and provenance tracking.Multi-LLM Strategy — Develop a strategy for selecting models per agent, establishing structured output contracts, and creating evaluation frameworks.Compliance & Security — Design systems that operate within a zero-trust model, ensuring agents verify against original data and manage outbound content securely to mitigate risks.QualificationsA minimum of 3 years of experience with Python and/or TypeScript in a production environment.Strong systems design acumen, with a focus on agent boundaries and failure modes.Proven hands-on experience with LLM-powered systems and document AI technologies.Ability to articulate when to use LLMs versus rules engines or traditional ML approaches.Experience in designing data pipelines and integration architectures in production.A strong understanding of security principles and their implications in system design.

Role overview Ebury is hiring an AI Platform Engineer for the Data Platform Engineering team based in Madrid (or Malaga). This hybrid position requires four days per week onsite and one day remote. The team is central to Ebury’s growth, focusing on building and maintaining the infrastructure that powers AI and agentic products throughout the company. What you will do Develop and maintain the Ebury Data Platform as part of the Data Platform Engineering team. Help build the Agentic Data Plane (ADP), which serves as a unified and governed interface for AI and agentic products. Design and implement features to simplify data communication and access, while maintaining governance, lineage, traceability, and replayability. Work closely with cross-functional domain teams to support secure and efficient deployment of AI and agentic products at scale. Work environment Hybrid schedule: four days onsite in Madrid (or Malaga), one day remote. Team values innovation, collaboration, and strong problem-solving skills. Supportive culture where team members are encouraged to grow and contribute to Ebury’s mission.

Are you passionate about leveraging AI technologies to enhance backend systems? Join docplanner as a Backend Engineer specializing in AI Integration. In this role, you will collaborate with a dynamic team to design, develop, and implement innovative solutions that integrate AI capabilities into our existing systems.Your expertise will contribute to optimizing processes and improving user experiences across our platforms. If you're ready to take your backend engineering skills to the next level while working with cutting-edge technology, we want to hear from you!