FullStack Consultant (TypeScript, React, and Next.js)
FullStack Consultant (TypeScript, React, and Next.js)
Kraków, PL, 30-302
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