(Senior) Java Developer - Freelance

DescriptionNetguru 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.We are looking for a Senior Backend Engineer with strong architectural skills to join a long-term project for a European client in the laboratory and biotech domain. This is a single-developer project, where you will work closely with the client's internal teams and laboratory stakeholders to clarify requirements, define scope, and improve existing backend processes. Strong communication skills are essential, as you will regularly attend technical discussions with LIMS and laboratory teams. The role involves hands-on development, refactoring legacy code, and contributing to a scalable and well-structured backend architecture. You must be based in the EU due to client requirements.Position: Senior Backend Engineer (Java / Architecture)Contract: Freelance / B2B – Remote (EU Only)Rate: 36–50 EUR/hourLanguage: English C1ResponsibilitiesWork independently as the sole backend engineer on the projectRefactor and modernize legacy backend systemsImprove and extend existing microservices and backend integrationsMaintain and develop REST and SOAP interfacesCommunicate with laboratory teams and LIMS stakeholders to define requirementsEnsure stable operation of backend services in an on-premise Kubernetes environmentCollaborate with internal client teams to maintain architectural consistencyRequirementsTech stack & requirementsSenior-level experience with Java (Spring / Spring Boot)Strong architectural and problem-solving skillsExperience designing and maintaining REST APIsKnowledge of SOAP servicesBackground in microservices environmentsPractical experience with Kubernetes (on-premise setups preferred)Experience working with or integrating LIMS systemsSolid understanding of refactoring and legacy code modernizationExcellent communication skills for direct cooperation with laboratory stakeholdersEnglish at C1 levelMust be based in the European UnionBenefitsIn return, we offer:100% remote, 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).What will happen next?We would like to know you better, so we will invite you for a meeting with our recruiter.Next, you'll be asked to solve the task or invited to an interview and pair programming with one of our iOS Developers.Looking for a full-time job? Check out our 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.