Job Description

Senior Full Stack Engineer

Department: Business Partner Transparency

Employment Type: Permanent

Location: Madrid

As a Senior Full-Stack Developer, you’ll play a key role in shaping the future of Business Partner Transparency (BPT) within our osapiens HUB. This enterprise-grade platform helps companies comply with critical ESG regulations like:

• The German Supply Chain Due Diligence Act (LkSG) – ensuring suppliers uphold human rights and environmental standards.
• The Whistleblower Directive – providing secure, anonymous reporting channels.
• The Corporate Sustainability Due Diligence Directive (CSDDD) – upcoming EU-wide sustainability compliance.

Our osapiens HUB is a modern, enterprise-grade development platform that enables businesses to build powerful applications without worrying about infrastructure, scaling, or failover. You’ll help develop and refine this cutting-edge, serverless ecosystem while delivering meaningful solutions for international clients.

This role is based in Madrid, where you'll collaborate with a talented, forward-thinking team. We embrace a hybrid work model, with three days a week in the office, ensuring the perfect balance between in-person collaboration and remote flexibility.

Your Responsibilities

• Design, build, and optimize full-stack features using modern back-end technologies, ensuring scalability and maintainability.- Front End experience is good to have.
• Develop and enhance innovative software solutions that automate complex compliance workflows for businesses of all sizes.
• Collaborate closely with product managers, designers, and engineers in small, agile squads (5-7 people) to define, refine, and implement features.
• Ensure high-quality, secure, and efficient code through rigorous reviews, automated testing, and continuous integration/deployment (CI/CD) practices.
• Own the architecture and design of JavaScript-based solutions, optimizing for performance, reliability, and user experience.
• Contribute to technical strategy and decision-making, identifying opportunities for innovation and process improvements.
• Mentor and support junior developers, fostering a culture of learning and technical excellence within the team.

Your Experience

• Strong experience (6+ yrs) in full-stack development with a focus on Backend (Node.JS and TypeScript) React.JS is desirable
• Expertise in web services development and integration (REST, GraphQL, etc.).
• Familiarity with Git for version control and collaboration.
• Strong product mindset – you think beyond code, considering user experience, business impact, and scalability.
• Agile experience – comfortable working in sprints, participating in stand-ups, and iterating quickly.
• Excellent communication skills in English (C1). Spanish is a bonus but not necessary.