Senior Java Backend Developer (m / w / d)

🌍 About Adfinis

At 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 Do

Be 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 For

Bachelor’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 Points

Experience 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.

Open Source - Our Key to Innovation and Sustainable Digitalization

As open-source professionals, we offer a wide range of services and solutions from a single source. Open technologies and standards are our key to innovation. With our tailor-made offer, we have the optimal solution for every area in IT.