Backend Engineering Intern (Java / Spring Boot)

Build the backend services behind Atomity’s cloud decision platform, working on secure APIs, multi-tenant architecture, cloud integrations and production-grade enterprise systems.

About the Role

This is a remote internship role, UNPAID.

As a Backend Engineering Intern, you will work on the Java and Spring Boot services behind Atomity’s cloud decision platform.

Atomity helps organisations understand their cloud environments, evaluate infrastructure options and make better workload placement decisions across hyperscalers, European cloud providers and private infrastructure.

You will help build the backend services that power these workflows, including APIs, data models, authentication and authorization, cloud integrations and internal platform services.
This is not a tutorial or simulated internship project. You will contribute to a real B2B SaaS product where security, data isolation, maintainability and scalability matter.

What You Will Work On

1. Build and extend backend services using Java and Spring Boot.
2. Design and implement REST APIs used by Atomity’s frontend and internal services.
3. Work on multi-tenant architecture, including tenant isolation and access control.
4. Design PostgreSQL schemas and work with relational data models.
5. Implement database migrations and maintain data consistency.
6. Work on authentication, authorization and role-based access control.
7. Integrate backend services with cloud-provider APIs and Atomity’s internal platform components.
8. Implement validation, exception handling and structured logging.
9. Write unit and integration tests for backend services.
10. Work with Docker and containerised development environments.
11. Participate in code reviews and improve existing backend architecture.
12. Help build backend components that can evolve into reliable production services.

Tech Stack

1. Java
2. Spring Boot
3. Spring Web / REST APIs
4. Spring Security
5. PostgreSQL
6. JPA / Hibernate
7. Maven or Gradle
8. Docker
9. Git
10. REST / JSON
11. Cloud APIs
12. Kubernetes exposure

Requirements

1. Currently pursuing or recently completed a B.Tech, M.Tech, M.Sc. or related Computer Science degree
2. Good understanding of Java fundamentals
3. Basic experience with Spring Boot or strong motivation to learn it
4. Understanding of object-oriented programming
5. Basic understanding of REST APIs and HTTP
6. Familiarity with SQL and relational databases
7. Understanding of Git and basic software-development workflows
8. Strong logical problem-solving skills
9. Comfortable learning independently and taking ownership of assigned work

Nice to Have

1. Experience building a project using Spring Boot
2. Familiarity with Spring Security
3. Experience with PostgreSQL
4. Understanding of JPA or Hibernate
5. Exposure to Docker
6. Basic knowledge of AWS, Azure, GCP or another cloud platform
7. Familiarity with microservices or distributed systems
8. Basic understanding of Kubernetes

What You Will Learn

1. How production backend services are structured using Java and Spring Boot.
2. How multi-tenant B2B SaaS platforms isolate customers and data.
3. How authentication, authorization and access control work in enterprise applications.
4. How backend services communicate with frontend applications and other services.
5. How PostgreSQL schemas and migrations are managed in a growing product.
6. How cloud-provider integrations are implemented.
7. How testing, logging and error handling are handled in production systems.
8. How Docker and cloud-native environments fit into backend development.
9. How engineering decisions change as a product moves from early development toward production.
10. How a European B2B cloud technology company builds its backend architecture.

Why Join Atomity?

1. Work on a real enterprise cloud product, not a simulated internship project.
2. Work directly with Atomity’s founders and engineering team.
3. Build backend components that become part of the core product.
4. Gain practical experience with Java, Spring Boot, PostgreSQL and cloud-native systems.
5. Learn how secure multi-tenant SaaS platforms are designed.
6. Gain exposure to multi-cloud infrastructure and enterprise cloud architecture.
7. High ownership from day one.
8. Opportunity to grow into a paid, full-time role as Atomity scales.