Senior Java Backend Engineer – Freelance (Barcelona, Hybrid)

We are looking for a Senior Java Backend Engineer to join a long-term freelance project in Barcelona (hybrid: 3 days onsite, 2 remote). This role is part of a strategic transformation initiative in the financial sector, modernizing data management systems with cloud-native technologies and agile methodologies. Start date: September 1st, 2025 Location: Barcelona (Hybrid) Duration: Long-term freelance contract Responsibilities Build and optimize back-end services with Java 8/11/21, Spring Boot, Microservices . Translate complex business needs into scalable solutions. Improve GUI functionality in collaboration with frontend teams. Implement best practices in security, compliance, and governance . Work with Apache Kafka & Apache Spark for real-time data pipelines. Deploy and manage applications in OpenShift / Azure with Kubernetes & Docker. Collaborate in agile cross-functional teams (SCRUM, SAFe) . Provide technical leadership and mentor junior developers. ✅ Requirements 7 years of Java development (Java 8, ideally 17/21). Strong expertise in Spring Boot, Microservices, REST APIs . Experience with Kubernetes, Docker, CI/CD pipelines . Cloud knowledge ( OpenShift, Azure ). Familiarity with PostgreSQL, Hibernate, distributed systems . Proficiency in Kafka, Spark for real-time streaming. Awareness of Angular and testing frameworks (JUnit, Jasmine, Karma). Previous work in financial services / trading platforms is a big plus. Fluent English & Spanish.

Location: Catalonia, ES

Posted Date: 8/21/2025