Fullstack Engineer (Frontend focused)

Flix; Warszawa; A distancia; PLN 83.000 - 131.000; Jornada completa

Descripción de la vacante

FlixTrain is seeking a skilled Fullstack Engineer (Frontend focused) for a service agreement collaboration (B2B) to help build internal tools for timetable planning and vehicle allocation, reducing manual work. You’ll shape new products in a greenfield environment with React and TypeScript, while contributing to frontend architecture and collaborating with a distributed team in an Agile setup.

The role is open to contractors based in Poland, offering a flexible remote/contract arrangement and

Formación

• Experience with React and TypeScript in production.
• Strong HTML/CSS skills and responsive design.
• Backend experience with Node.js or similar and GraphQL APIs.
• Experience writing tests with Vitest or similar.
• Knowledge of event-driven architectures and microservices.
• Excellent written and spoken English; Agile team experience.

Responsabilidades

• Develop frontend features using React/TypeScript for internal tools.
• Collaborate on backend tasks including GraphQL APIs and server-side logic.
• Contribute to frontend architecture decisions and code reviews.
• Write automated tests to ensure reliability and maintainability.
• Work with internal stakeholders to translate needs into practical solutions.

Conocimientos

React

TypeScript

HTML

CSS

Node.js

GraphQL APIs

Vitest

Event-driven systems

English

Agile

Domain knowledge (transport/logistics)

Herramientas

GraphQL

Spring Boot / Spring Framework

Kafka

AI-assisted coding

Descripción del empleo

We are looking for a skilled Fullstack Engineer (Frontend focused) for service agreement collaboration (B2B contract) to cooperate with a team dedicated to Network Planning at FlixTrain - building internal tools that help plan the timetable and vehicle allocation, reduce manual processes, and increase productivity. This is a greenfield environment with plenty of room to shape new products from the ground up and explore innovative solutions for our internal users.

Scope of Services

You will independently develop and deliver high-quality frontend features, with occasional backend work, within a self-organized, cross-functional, distributed team. This includes building intuitive user interfaces with a focus on the experience of our internal users. You will also help drive frontend architecture decisions and contribute to technical quality across teams through code reviews and close collaboration.

About the Engagement

• Design and build internal web applications that automate and simplify FlixTrain Network Planning workflows
• Develop modern, responsive user interfaces with React and TypeScript and contribute to a consistent, reusable frontend architecture
• Design and implement backend functionality, including GraphQL APIs, server-side logic and database models
• Work with internal users and stakeholders to understand their needs and turn them into practical product solutions
• Write and maintain automated tests, to ensure reliability and maintainability
• Collaborate with other engineers across a distributed architecture within an Agile environment
• Document technical decisions, solutions and ways of working

About You

Must have:

• Hands‑on experience with React (React 19 in our stack) and TypeScript, with a strong command of HTML and CSS
• Experience with an object‑oriented backend language. Java is not required, but preferable: Node.js or similar is acceptable, provided you have real backend development experience, not just scripting
• Hands‑on experience in backend web application development: building and designing GraphQL APIs, server‑side logic and database design
• Experience writing tests and working with test runners such as Vitest
• Understanding of event‑driven systems and how to work with them
• Solid written and spoken English skills
• Experience working in an Agile setup
• Curiosity about the business domain. Interest in transportation, logistics or similarly complex domains is a good signal, as is the ability to explain such a domain clearly

Nice to have:

• GraphQL: used in our stack (Spring for GraphQL, Apollo, gql.tada)
• Java and Spring Boot / Spring Framework
• Kafka
• Experience with agentic or AI‑assisted coding
• Contract type: Cooperation based on a service agreement (B2B/freelance contract), not an employment contract
• Working model: Independent contractor responsible for delivering agreed services and submitting invoices
• Location: Open for contractors based in Poland