Fullstack Developer (Node.js/React)

We've been building digital products for over 10 years, with a strong focus on Blockchain-based applications. At 4soft, people come first - it's our team of passionate technologists that enables us to work with international clients and deliver innovative solutions. We believe in transparency, effective teamwork, and achieving real business outcomes for those we serve.

Join our client's team, a fast-growing scale-up in the fiat-to-crypto payments space, and take ownership of core parts of its onramping platform. You'll spend roughly 70% of your time on backend (Node.js, TypeScript, APIs, cloud infrastructure) and 30% on frontend (React, TypeScript). You're not expected to be a specialist in both - but you are expected to be genuinely capable across the stack and comfortable context-switching between the two.

As a Fullstack Developer, you will be responsible for

• Designing and building robust, scalable backend services and APIs in Node.js and TypeScript
• Develop and maintain React-based frontend interfaces that are performant and maintainable
• Working closely with product to shape features from discovery through delivery, not only building to a spec
• Owning work end to end: scoping, building, shipping and monitoring
• Writing secure, well-tested, production-ready code for systems with real uptime requirements
• Contributing to and improving CI/CD pipelines, deployment processes and cloud infrastructure
• Taking part in code reviews, architectural discussions and technical decision-making
• Helping keep production systems reliable and observable, and responding when things go wrong

What we expect from you

• Strong, production-proven JavaScript/TypeScript experience, including real use of the type system
• Solid backend experience. Node.js is preferred; excellent backend experience in Java, Go or Python is acceptable
• Solid frontend experience building and maintaining real applications - React is preferred, but strong experience with another popular framework (Vue, Angular) is equally welcome
• Hands-on production experience with cloud infrastructure on AWS, GCP or Azure
• Working understanding of CI/CD pipelines and modern deployment practices
• A security-conscious approach: attack surfaces, data handling and least-privilege access are habits
• Genuine interest in crypto and in the company's product
• Ability to work with product teams, translate between technical constraints and business needs, and push back when needed
• English proficiency at C1 level or above (for international client collaboration)
• Polish language skills at B2 level or above (for smooth communication with the team)

Great if you also bring

• AWS experience specifically
• Terraform for infrastructure-as-code
• Kubernetes for container orchestration
• Fintech experience, particularly payments, transactions or regulated financial systems

What helps us stay balanced

• Grow your skills and hobbies with us - make use of a dedicated training and wellbeing budget
• Work from home or the office - your choice, up to 100% remote
• Access to specialists whenever you need them via our LuxMed healthcare package
• If the gym is your second home, activate a Multisport card with us
• Looking for a long-term home? You're in the right place - stable collaboration, no dress code, no heavy atmosphere
• Our team knows how to have fun: board games, city outings, go-kart races, laser tag, great food on team retreats - we take integration seriously (in the best way :)