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