Middle Fullstack Engineer (Kotlin&React)

Engg; Poland; On-site; PLN 140,000 - 210,000; Full time

Job summary

Xebia is a global AI-first, digital transformation, and engineering partner. We design and build scalable products and data-driven solutions across Europe, employing an engineering-first culture and a strong emphasis on growth and knowledge sharing.

The role involves developing microservices with Java/Kotlin, crafting REST APIs, and implementing frontend components with React. You will collaborate across backend and frontend areas and engage with external partners to deliver features rapidly and

Qualifications

• 3+ years of commercial experience in software development.
• Strong knowledge of Java and Kotlin.
• Experience with microservice architecture.
• Hands-on experience with React and modern JavaScript.
• Good knowledge of HTML and CSS.
• Solid understanding of REST API design and consumption.
• Practical experience using JSON.
• Willingness to work across both backend and frontend development.
• English at min. B2 level, Polish at min. B1 level.
• Willingness to occasional visits to the Warsaw office (1–2 days per quarter).
• Work from the EU region and a work permit are required.

Responsibilities

• Develop and enhance microservices using Java and Kotlin.
• Design, develop, and modify REST APIs and backend mocks.
• Build web components and registration flows using React.
• Work across backend and frontend areas, adapt to project needs.
• Integrate solutions with external business partners and support partner-facing features.
• Collaborate with the team to deliver new features quickly and efficiently.
• Contribute to continuous improvement of product and technical solutions.

Skills

Java

Kotlin

Microservices

React

JavaScript

HTML

CSS

REST APIs

JSON

English (B2)

Polish (B1)

AI-powered tools

Tools

Docker

GitLab CI

AWS

Azure

GCP

Job description

Xebia is a global AI-first, digital transformation, and engineering partner. With over 25 years of experience and a team of 5,000 professionals across 16 countries, we help organizations design and build scalable products, platforms, and data-driven solutions. We specialize in Artificial Intelligence, Data and Cloud, Intelligent Automation, and Digital Products, combining deep technical expertise with a strong focus on engineering excellence and a people-first culture. In the CEE region, we’re a team of nearly 1,000 experts delivering modern applications, data platforms, and AI solutions for clients such as McLaren, Aviva, Deloitte, Spotify, Disney, ING, UPS, Tesco, Truecaller, AllSaints, Volotea, Schmitz Cargobull, Allegro, InPost, and many, many more. We work with leading technologies including AWS, Azure, GCP, Databricks, and Snowflake, and combine strong engineering culture with a consulting mindset and a continuous focus on growth and knowledge sharing.

You will be: developing and enhancing microservices using Java and Kotlin, designing, developing, and modifying REST APIs and backend mocks, building web components, purchase flows, and registration processes using React, working across both backend and frontend areas, adapting to changing project needs, integrating solutions with external business partners and supporting partner-facing functionalities, collaborating with the team to deliver new features quickly and efficiently, contributing to the continuous improvement of the product and technical solutions.

Your profile: 3+ years of commercial experience in software development, good knowledge of Java and Kotlin, practical experience working with microservice architecture, hands‑on experience with React and modern JavaScript, good knowledge of HTML and CSS, solid understanding of REST API design and consumption, practical experience working with JSON, willingness to work across both backend and frontend development, practical experience using AI‑powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision‑making in software delivery, ability to quickly switch between different technological areas and tasks, good communication and collaboration skills, English at min. B2 level, Polish at min. B1 level, openness to occasional visits to the Warsaw office (1‑2 days per quarter). Work from the European Union region and a work permit are required.

Nice to have: experience with Docker and CI/CD processes, particularly GitLab CI, experience working with cloud environments, understanding of UX/UI principles, familiarity with Responsive Web Design (RWD), experience integrating with external partner systems, experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work, interest in and familiarity with emerging AI‑driven practices (e.g. agent‑based workflows, automation patterns, AI‑augmented development), with a willingness to explore and experiment beyond standard approaches.

Recruitment Process: CV review – HR call – Technical Interview – Client Interview – Decision