Senior Java Developer (Polish-speaking) - Freelance

Employment: Contract Netguru is a trusted partner in digital commerce. The company helps leading brands modernize B2B solutions, marketplaces, and retail ecosystems. Since 2008, it has empowered businesses with cutting-edge technology, AI-powered personalization, and world-class engineering and design teams. A certified B Corporation®, Netguru is trusted by major brands including IKEA, VW, OLX, Delivery Hero, Żabka, Wolt, Careem, and Vinted. How freelancing works at Netguru? As a Netguru freelancer , you can choose what works well for you. You decide when, where, and how you work on projects and tasks. We match you with work that fits your skills. Plus, you have access to various opportunities across different industries and companies. That means you will not only gain more experience, but also develop various skills. But there's more. Netguru freelancers can benefit from full-time collaboration and really be a part of the team. So, are you ready to make an impact? Join Netguru, and let's build beautiful software together. We are looking for a Senior Java Developer located in Poland. Start date : around 09.11.2026 Duration: 3-6 months Full-time Hybrid work: 1-2 day per month form office in Warsaw CET working hours Rate : up to 160 PLN/h Requirements Fluent Polish . English proficiency sufficient to read technical documentation, handle business correspondence, and communicate verbally with external international vendors. Knowledge of Java, Spring Boot, Hibernate/JPA, SQL, JUnit, Kafka. At least 4 years of experience as a software developer. Solid knowledge of design patterns and object-oriented programming principles. Knowledge of Azure cloud services. Ability to work with data mappings. Knowledge of the JSON data format. Knowledge of SQL. Building data pipelines. Ability to work with REST APIs. Knowledge of creating topics (Kafka / Debezium). Benefits In return, we offer: Flexible work; work with an experienced team of developers and continuous development of your hard and soft skills; dev-friendly processes such as Continuous Integration, Continuous Delivery, Code Review and bug bashes; long-term collaboration on challenging products (FinTech, B2B software, E-commerce and more). Looking for a full-time job? Check out our Career Page and find out more about our open recruitment processes. If you need any disability-related adaptation at any step of the recruitment process – simply let the recruiter know! We'd be happy to help.