Email Security Engineer; m​/f​/d

Our mission:

Are you a motivated Software Engineer looking to make an impact by strengthening digital security and sovereignty in the public sector in Germany? At Open-Xchange, we develop and deliver open-source communication and collaboration technologies for email and DNS security that connect millions of people worldwide.

• Solid hands-on experience in software development, preferably in Java-based systems.
• Strong motivation and passion for working with the mentioned tech stack.
• Experience in secure communication technologies and cryptographic concepts (e.g. PGP, S/MIME, key handling, certificate chains, message signing).
• Experience with RESTful APIs, microservices, and distributed systems.
• Familiarity with end-to-end encryption concepts or architectures is a strong plus.
• Knowledge of email standards (SMTP, IMAP, MIME) is beneficial.
• Strong verbal and written communication skills in both German and English.
• Intrinsic motivation to take ownership and a passion for open-source technologies, thriving in a low-hierarchy environment.
• Comfortable working in a remote-first environment with multicultural teams across different time zones.

• The flexibility to work 100% remotely ensures a work environment that suits you best.
• Flexible working hours that allow you to successfully combine your home and family responsibilities with work.
• Getting together in-person for workshops and fun team events.
• Time off to volunteer – and mental health support when you need it.
• We provide financial relief through corporate benefits and a subsidy for ergonomic chairs and desks.
• We can discuss further location-related benefits together in an initial talk.

Join us in our fight for an open internet and deliver added value! Click “Apply now” to submit your application.

• We work in a non-hierarchical organization that empowers everyone to take responsibility, stay focused, and contribute directly to the company’s success and customer value.
• We value expertise and continuous professional development. Our professionals work closely with experienced colleagues, take ownership of their work, and continuously expand their skills
• Openness and diversity are core to OX. Different perspectives, backgrounds, and ways of thinking strengthen our collaboration and help us see the bigger picture.

Reach out to Justin () from the People Team. He will be able to discuss current opportunities and tell you more about our exciting vision and mission @OX.

As part of the cross-functional OX Public Sector team, you will help develop secure email solutions that strengthen digital sovereignty in Germany. As a Java Developer, you will enhance the encryption framework of OX App Suite, including PGP, S/MIME, and end-to-end encryption (E2EE). You will work closely with product, security, and UI colleagues to deliver a robust and user-friendly encryption experience.

• Maintain and improve existing backend and middleware components.
• Design and develop new services and APIs.
• Contribute to email encryption features (PGP, S/MIME, and end-to-end encryption).
• Collaborate with security and product colleagues to deliver reliable, user-friendly solutions.
• Support CI/CD pipelines, containerized deployments, and system operations.
• Write tests, review code, and document your work.

• Programming languages and frameworks:
  Java, Spring Boot, OSGi
• Containerization and orchestration:
  Docker, Kubernetes, Helm
• CI/CD:
  Git Lab CI, Jenkins
• Build tools:
  Gradle
• Databases:
  Maria
  
  DB/MySQL, Redis