Java Backend Intern

This is a full-time, remote internship role.

As a Java Backend Intern, you will work on the backend services behind Atomity’s cloud decision platform. Atomity helps organisations understand cloud environments, compare infrastructure options and make better workload placement decisions across hyperscalers, European cloud providers and private infrastructure.

You will help build secure backend services, APIs and data models that support Atomity’s product workflows. You will work with Java, Spring Boot and PostgreSQL while learning how multi-tenant enterprise systems are designed, tested and operated.

• Build and extend backend services using Java and Spring Boot.
• Design and implement REST APIs used by Atomity’s frontend and internal services.
• Work on multi-tenant architecture, including tenant isolation and access control.
• Design PostgreSQL schemas and work with relational data models.
• Implement database migrations and maintain data consistency.
• Work on authentication, authorization and role-based access control.
• Integrate backend services with cloud-provider APIs and Atomity’s internal platform components.
• Implement request validation, exception handling and structured logging.
• Write unit and integration tests for backend services.
• Run and test services using Docker and containerised development environments.
• Participate in code reviews and improve existing backend architecture.

• Java
• Spring Boot
• Spring Web / REST APIs
• Spring Security
• PostgreSQL
• JPA / Hibernate
• Maven or Gradle
• Docker
• Git
• REST / JSON
• Cloud APIs
• Kubernetes exposure

• Currently pursuing or recently completed a degree in Computer Science, Software Engineering or a related field.
• Good understanding of Java fundamentals and object-oriented programming.
• Basic experience with Spring Boot or a strong interest in learning it.
• Understanding of REST APIs, HTTP and backend application concepts.
• Familiarity with SQL and relational databases.
• Basic understanding of Git and software-development workflows.
• Strong logical problem-solving skills.
• Willingness to learn, communicate clearly and take ownership of assigned work.

• Experience building a project using Spring Boot.
• Familiarity with Spring Security.
• Experience with PostgreSQL.
• Understanding of JPA or Hibernate.
• Exposure to Docker.
• Basic knowledge of AWS, Azure, GCP or another cloud platform.
• Familiarity with microservices or distributed systems.
• Basic understanding of Kubernetes.

• Duration: 3–6 months
• Location: Remote only
• Start date: Flexible

• How production backend services are structured using Java and Spring Boot.
• How multi-tenant B2B SaaS platforms isolate customers and data.
• How authentication, authorization and access control work in enterprise applications.
• How backend services communicate with frontend applications and other services.
• How PostgreSQL schemas and migrations are managed in a growing product.
• How cloud-provider integrations are implemented.
• How testing, logging and error handling are handled in production systems.
• How Docker and cloud-native environments fit into backend development.

• Work directly with Atomity’s founders and engineering team.
• Real product experience, not practice projects.
• Build backend components that become part of the core product.
• Gain practical experience with Java, Spring Boot, PostgreSQL and cloud-native systems.
• Gain exposure to multi-cloud infrastructure and enterprise cloud architecture.
• High ownership from day one.
• Opportunity to grow into a full-time role as Atomity scales.

To apply for the Java Backend Intern position, please complete and submit the application form on this page. Make sure to include:

• Your resume/CV (PDF, DOC, or DOCX formats, max 10 MB).
• A link to your GitHub profile, portfolio or relevant backend projects.
• A link to your LinkedIn profile.
• A brief note on why you are interested in backend engineering and joining Atomity.

Technical Issues?
If you experience any issues while submitting the form, please send your application details and attachments directly to career@hr.atomity.de with the subject line “Java Backend Intern”.