Senior Java Backend Developer (m/w/d)

🌍 About AdfinisAt Adfinis, we’re not just another software company – we’re an Open Source powerhouse with a passion for clean, reliable, and scalable technology.With roots in Switzerland and teams across Germany, the Netherlands, Australia, and Egypt, we build solutions that empower organizations to move fast, stay secure, and scale sustainably.As a Senior Java Backend Developer, you’ll play a key role in designing and building high-performance microservices that form the backbone of our clients’ infrastructure. You’ll work closely with global teams to deliver modern, cloud-native systems that make an impact — while staying true to our Open Source values.Tasks🚀 What You’ll DoBe a key member of the Backend Engineering Team, designing and maintaining scalable, high-performance Java microservices Develop and optimize RESTful APIs that connect front-end, data, and external systems via API Gateways Build cloud-native microservices deployed on AWS, Azure, or GCP environments Write clean, testable, and maintainable code following SOLID, DDD, and Clean Code principles Contribute to the architecture and design of distributed systems and domain models Collaborate closely with Frontend Developers, DevOps Engineers, and Product Owners in Agile/Scrum teams Participate in code reviews, pair programming, and drive continuous improvement initiatives Ensure system reliability, security, and observability using modern monitoring and logging practices Support CI/CD pipelines, containerization, and deployment automation with Docker and Kubernetes Requirements💡 What We’re Looking ForBachelor’s degree in Computer Science, Software Engineering, or equivalent 5+ years of experience in Java/Spring backend development Strong knowledge of Java 17+, Spring Boot, Spring Security, Spring Cloud Deep understanding of OOP, Design Patterns, and Microservices Architecture Proven experience building REST APIs, SOAP Web Services, and writing clean, maintainable code Proficient with JPA/Hibernate, SQL, and NoSQL databases (PostgreSQL, MySQL, MongoDB, Redis) Familiar with cloud services and API Gateways (Spring Cloud Gateway, AWS Lambda, ECS, S3, Azure/GCP equivalents) Experience with event-driven systems and message brokers (Kafka, RabbitMQ) Solid understanding of Clean Architecture, testing (JUnit, Testcontainers), and automation Used to working in Agile environments with GitLab, Jira, and Confluence Knowledge of containerization and cloud deployments (Docker, Kubernetes, Helm) Passionate about performance optimization and robust software design Strong communicator with a solution-oriented mindset and focus on delivery excellence 🌟 Bonus PointsExperience with Keycloak, OAuth 2.0, or JWT authentication Familiarity with CI/CD tools (GitLab CI, Jenkins, ArgoCD) Hands-on with Reactive Programming (WebFlux, Reactor) Contributions to Open Source projects or mentoring experience in dev teams Benefits🎁 Why You’ll Love Working Here🌐 Remote-First setup with flexibility and autonomy🤝 Collaborate with international Open Source experts across time zones🚀 Work on modern, cloud-native systems with cutting-edge technologies💡 Continuous learning — certifications, conferences & mentoring included❤️ A culture that celebrates team spirit, ownership, and engineering excellence👉 Ready to Build What Matters?Join Adfinis LLC and bring your Java mastery to a team that’s shaping the future of Open Source infrastructure.If you thrive on clean code, collaboration, and crafting systems that just work — we can’t wait to meet you. 🚀Adfinis LLC – Open Source. Open Minds.