Senior Java Developer

O projekcie: Who We Are While Xebia is a global tech company, our journey in CEE started with two Polish companies – PGS Software, known for world-class cloud and software solutions, and GetInData, a pioneer in Big Data. Today, we’re a team of 1,000+ experts delivering top-notch work across cloud, data, and software. And we’re just getting started. What We Do We work on projects that matter – and that make a difference. From fintech and e-commerce to aviation, logistics, media, and fashion, we help our clients build scalable platforms, data and AI solutions, and cutting-edge applications to shape the future of tech. Our clients include McLaren, Aviva, Deloitte, Spotify, Disney, ING, UPS, Tesco, Truecaller, AllSaints, Volotea, Schmitz Cargobull, Allegro, InPost, and many, many more. We value smart tech, real ownership, and continuous growth. We use modern, open-source stacks, and we’re proud to be trusted partners of Databricks, dbt, Snowflake, Azure, GCP, and AWS. Fun fact: we were the first AWS Premier Partner in Poland! Beyond Projects What makes Xebia special? Our community. We support tech communities, organize meetups (Software Talks, Data Tech Talks), and have a culture that actively support your growth via Guilds, Labs, and personal development budgets — for both tech and soft skills. It’s not just a job. It’s a place to grow. What sets us apart?  Our mindset. Our vibe. Our people. And while that’s hard to capture in text – come visit us and see for yourself. Wymagania: - 5+ years of professional experience in Java backend development, - strong experience with Java (8+) and Spring Boot, - experience in business product development within fintech environments, - experience working on B2B products, - hands-on experience with high-concurrency systems, multi-threading, and high-volume traffic environments, - proven experience working with large-scale data processing systems, - solid knowledge of technologies such as MyBatis, Redis, and message queue systems, - experience working with relational databases such as MySQL, including writing complex queries and performance tuning, - experience working with Elasticsearch and big data technologies such as Hadoop, - experience with messaging systems (queues) and event-driven architectures, - experience with unit and integration testing, - experience integrating with third-party services and APIs, - strong debugging and problem-solving skills, - solid understanding of software design patterns and backend architectures, - good communication skills and ability to work in a team environment, - immediate availability or a short notice period is preferred. Work from the European Union region and a work permit are required. Nice to have: - familiarity with RPC frameworks such as Apache Dubbo, - experience working with systems serving large-scale user bases, - understanding of distributed systems and microservices architecture. Codzienne zadania: - designing, developing, and maintaining high-performance backend systems using Java and Spring Boot, - working on transaction, payment, and cashier-related functionalities within a complex trading platform, - building and maintaining RESTful and RPC APIs (e.g. using Apache Dubbo), - developing solutions capable of handling high-volume traffic, high concurrency, and multi-threaded environments, - processing and optimizing large volumes of data within distributed systems, - collaborating with cross-functional teams to deliver scalable and reliable systems, - integrating backend services with third-party applications and external systems, - troubleshooting, debugging, and optimizing system performance in production environments.