FullStack Consultant (TypeScript, React, and Next.js)

Type of contract: B2B contract 

Salary range: 90 - 125 PLN/H

What will you do?

You will build and improve user-facing experiences and product APIs that support modern data services. The role combines strong frontend development with practical full-stack delivery, translating product needs into accessible, reliable, and secure solutions across browser and service layers.

Your tasks

• Design, build, and maintain TypeScript and Next.js user interfaces that are responsive, accessible, and aligned with business needs


• Deliver end-to-end product features across frontend and backend integration layers


• Collaborate with product, UX, backend, and data teams to refine user journeys, data contracts, and acceptance criteria


• Build secure and maintainable frontend solutions using reusable components and well-structured state management


• Integrate frontend applications with Java 21 and Spring Boot services


• Diagnose and resolve UI defects, API integration issues, performance bottlenecks, and production issues


• Develop and maintain unit, integration, and regression tests


• Support application quality through observability, logging, performance tuning, and production follow-up


• Maintain high engineering standards for code quality, code reviews, secure development, and deployment readiness

Requirements

• Strong experience with TypeScript, React, and Next.js


• Good understanding of modern frontend architecture, component design, state management, routing, API integration, and accessible UI patterns


• Experience delivering full-stack features across browser and service layers


• Working knowledge of Java and modern Spring Boot application patterns


• Experience with REST APIs, DTOs, authentication flows, and integration contracts


• Ability to write clean and maintainable code and participate in technical design and code reviews


• Understanding of secure frontend and backend practices, including token handling, role-based access, and safe data handling


• Strong problem-solving skills and experience investigating production issues across UI and API layers


• Good communication and collaboration skills


• Openness to work hybrid from our client's office (Kraków) 6 days a month

Nice to have

• React Query, Redux Toolkit, TanStack Query, or similar state management and data-fetching solutions


• Axios, forms, validation, and component libraries


• Spring Web, Spring Security, or Spring Data JPA


• PostgreSQL, database design, or database migration patterns


• OpenTelemetry, Micrometer, structured logging, or production monitoring tools


• Cloud-native or containerised delivery environments


• JUnit 5, Vitest, Playwright, or equivalent testing frameworks