Senior Fullstack Developer (React / Next / Node)

MultiSafepay is a leading payment service provider, offering omnichannel and advanced payment solutions to businesses across Europe. We are innovative and fast-growing, building powerful solutions that transform the way our clients do business. We focus on delivering real solutions to their challenges and always stay ahead of the curve. In short, we are a true FinTech.

We're on a mission to make payments simple, secure, and accessible for every business. With powerful in-house technology and deep expertise, our modular platform brings online, in-person, and cross-border payments together in one place — giving merchants the flexibility to scale on their own terms. Through a partnership-first approach, we tackle complexity head-on, keep payments running smoothly, and boost success rates. It's how we level the playing field for businesses of all sizes and ambitions.

About the role

Our Technology team builds and owns the platforms and products that power MultiSafepay's payment solutions. Working across a modern stack — React, Next.js, Node.js, NestJS, PostgreSQL, and headless commerce integrations via MedusaJS — the team takes full ownership of features from concept through to production, with a strong emphasis on scalability, performance, and clean architecture.

We are looking for a Senior Fullstack Engineer to join this team. In this role, you will be hands-on across the full stack — designing and building frontend features, contributing to backend services, and shaping database and system architecture. You will also play a key role in mentoring junior and mid-level developers, and if you bring React Native experience, you'll have the opportunity to contribute to our mobile apps too.

What you'll be doing:

• Designing and implementing scalable, high-quality frontend features using React and Next.js, with a focus on performance and user experience

• Contributing to backend development with Node.js and NestJS, and modelling and optimising PostgreSQL schemas, queries, and migrations

• Defining system architecture, feature design, and data flow across the full stack

• Integrating REST and GraphQL APIs and working with headless commerce platforms such as MedusaJS

• Taking ownership of features from concept through to production release, writing clean, well-tested, and maintainable code throughout

• Mentoring and guiding mid-level and junior developers across the team

What you'll need:

• 5+ years of professional web development experience, with deep expertise in React and Next.js (SSR, SSG, routing, and performance tuning)

• Strong proficiency in JavaScript and TypeScript, with hands-on Node.js experience (NestJS a strong plus)

• Solid knowledge of PostgreSQL including schema design, query optimisation, and migrations

• Experience with system design, feature architecture, and data flow modelling across the stack

• Familiarity with headless commerce ecosystems such as MedusaJS, Shopify Headless, or Saleor

• Strong problem-solving skills and the ability to thrive in a fast-paced, collaborative environment

• Proficiency in English with strong communication skills

• Production experience with React Native is a strong plus, as is exposure to Docker, CI/CD pipelines, and AWS

What you'll get from us:

• A competitive salary and benefits package, including comprehensive health insurance

• Relocation support

• Opportunities for professional growth

• A diverse role within a dedicated international team of enthusiastic colleagues

• Office with an amazing view of the beach

• Free Spanish classes and optional afterwork sports activities