Software Development Engineer

Location: Barcelona, Spain About the Job Join Sanofi's Global eCommerce organization and help build the digital infrastructure that connects healthcare professionals, institutions, and patients to our portfolio of life-changing medicines. As a Software Development Engineer III , you will design, build, and operate production full-stack systems that power digital commerce experiences across multiple geographies and customer segments. This is a high-impact individual contributor role. You will own well-scoped features and services end to end, write high-quality code across the stack, and contribute to technical design discussions. You will work with increasing independence, with guidance from senior engineers on complex architectural and cross-team decisions, partnering closely with Product Owners, Designers, Commercial, and Operations stakeholders. Reliability, performance, and user experience directly affect Sanofi's ability to deliver medicines to patients worldwide. About Sanofi Sanofi is dedicated to supporting people through their health challenges. We are a global biopharmaceutical company focused on human health, committed to chasing the miracles of science to improve people's lives. Our team, across some 100 countries, is dedicated to transforming the practice of medicine by working to turn the impossible into the possible. We provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the center of our ambitions. At Sanofi, we believe our people are our greatest strength, and we are committed to creating an inclusive environment where diverse perspectives drive innovation. Our values — Aim Higher, Act for Patients, Be Bold, and Lead Together — guide everything we do. Main responsibilities Build and ship full-stack features and services across frontend (React, TypeScript), backend (Node.js, Java), APIs, and databases Contribute to technical design by authoring design documents, proposing options with clear trade-offs, and refining team standards Deliver high-quality software with unit, integration, and end-to-end testing, CI/CD pipelines, and thoughtful code reviews Build secure, performant microservices and APIs (REST, GraphQL), managing service communication, data consistency, and fault tolerance Translate business needs into well-defined technical tasks alongside Product Owners and Designers Implement observability and monitoring (e.g., DataDog), participate in on-call rotations, and drive root cause analysis and reliability improvements Support junior engineers and new joiners through code reviews, documentation, and team demos About you Experience: 5+ years of professional software engineering experience building and shipping full-stack web applications, with a track record of delivering features to production with increasing scope and independence Technical skills: Proficiency in JavaScript/TypeScript (Node.js) and at least one object-oriented language (Java, Python, C++, or similar); solid experience with React or an equivalent framework; experience building RESTful APIs and microservices; hands-on experience with a cloud platform (AWS, GCP, or Azure), Docker, and CI/CD; SQL and/or NoSQL databases; observability tools such as DataDog, Grafana, or similar Nice to have: Infrastructure as Code (Terraform, CloudFormation), Kubernetes, and SAP Commerce Cloud or Salesforce Commerce Cloud experience Soft skills: Ownership, pragmatic problem-solving, clear communication with technical and non-technical stakeholders, and a continuous learner mindset Experience in B2B, enterprise, or regulated industries is a plus Languages: Fluent English (written and verbal) Why choose us? Global impact at scale: your work will directly support patients and healthcare professionals across dozens of markets Complex, meaningful challenges: build high-scale systems at the intersection of healthcare and digital commerce Modern technology: work with cloud-native stacks on a platform that is actively being transformed Growth and collaboration: join talented engineers, product owners, and business leaders in a culture that invests in your development Flexibility and inclusion: competitive compensation, hybrid flexibility, and a people-first culture where every voice matters Mission-driven work: every line of code helps make life-changing medicines more accessible worldwide Pursue Progress . Discover Extraordinary . Join Sanofi and step into a new era of science - where your growth can be just as transformative as the work we do. We invest in you to reach further, think faster, and do what’s never-been-done-before. You’ll help push boundaries, challenge convention, and build smarter solutions that reach the communities we serve. Ready to chase the miracles of science and improve people’s lives? Let’s Pursue Progress and Discover Extraordinary – together. At Sanofi, we provide equal opportunities to all regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, protected veteran status or other characteristics protected by law. #LI-Hybrid #BarcelonaHub #SanofiHubs Pursue progress , discover extraordinary Better is out there. Better medications, better outcomes, better science. But progress doesn’t happen without people – people from different backgrounds, in different locations, doing different roles, all united by one thing: a desire to make miracles happen. So, let’s be those people. At Sanofi, we provide equal opportunities to all regardless of race, colour, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, ability or gender identity. Watch our ALL IN video and check out our Diversity Equity and Inclusion actions at sanofi.com ! The salary range for this position is :€49.600,00 - €74.400,00 Final compensation will be determined based on demonstrated experience, skills, location, and other relevant factors. Employees may be eligible to participate in Company employee benefit programs.