Senior Full Stack Engineer (Node.js / TypeScript / React)

About the role

We are looking for a Senior Full Stack Engineer to join an international engineering team based in Madrid and contribute to the development and evolution of a large-scale SaaS platform.

In this role, you will work across the entire technology stack, with a balanced focus on backend development using Node.js and TypeScript and frontend development using React.

Beyond writing high-quality code, you will actively participate in architectural decisions, shape technical solutions and take ownership of features throughout their lifecycle. You will collaborate closely with other engineers, Tech Leads and Product Managers to build scalable, reliable products that address complex business challenges.

This is an opportunity for an engineer who combines strong technical expertise across the stack with a genuine product mindset and an interest in influencing how software is designed, developed and evolved.

Key responsibilities

• Full Stack Development: Design, develop and maintain end-to-end product features, balancing backend services and frontend applications.
• Backend Engineering: Build scalable and maintainable services using Node.js and TypeScript, contributing to API design, business logic and microservices architecture.
• Frontend Engineering: Develop high-quality user interfaces and applications using React, focusing on usability, performance and maintainability.
• Software Architecture: Participate in architectural decisions, design patterns and the evolution of shared libraries and reusable components across the stack.
• Cloud Infrastructure: Work with a proprietary serverless cloud platform, contributing to the development and scalability of the technology ecosystem.
• End-to-End Ownership: Take responsibility for features from initial design and technical definition through implementation, testing, deployment and maintenance.
• Product Collaboration: Work closely with Product Managers, Tech Leads and fellow engineers to define solutions, challenge assumptions and translate business requirements into effective technical implementations.
• Engineering Excellence: Promote high development standards through code reviews, automated testing, CI/CD practices and continuous improvement.

Requirements

• At least 6 years of professional experience in software development, with substantial experience across both backend and frontend engineering.
• Experience working in product-based technology companies, ideally within SaaS environments or startups.
• Strong expertise in Node.js and TypeScript for backend development.
• Solid professional experience with React and modern frontend development practices.
• Experience designing and developing end-to-end features across the full stack.
• Good understanding of microservices, software architecture, scalable design patterns and API development.
• Ability to make technical decisions, contribute to architectural discussions and take ownership of software features.
• A strong product mindset, understanding the relationship between technical decisions, business objectives and user needs.
• Interest in cloud infrastructure and serverless architectures, including proprietary technology platforms.
• A consistent professional track record demonstrating commitment and long-term contribution to product development.
• Fluent English, with the ability to collaborate effectively with international engineering teams.

What we offer

• Competitive compensation
• Hybrid working model: 3 days per week at the Madrid office and 2 days working remotely.
• Technical ownership: The opportunity to influence architecture and contribute to the evolution of a proprietary serverless platform.
• Product impact: Work on scalable SaaS solutions used by thousands of international organisations.
• International engineering environment: Collaborate with experienced professionals in a growing technology company focused on engineering quality and product excellence.