Backend Developer (Java, Kotlin, Spring Boot)

Náplň práce, právomoci a zodpovednosti:

As a Backend Developer, you will be part of the Cassovia Code engineering team working on backend services for an international client. The project focuses on building cloud-native, scalable, and secure backend applications in a multi-tenant SaaS environment. You will work hands-on with Kotlin, Java, and Spring Boot, contributing to the design, development, and delivery of production-ready services with high quality and reliability standards.

You will collaborate closely with other developers and teams to ensure clean, testable, and maintainable code. The role is strongly engineering-focused, with emphasis on API design, security, testing, and cloud-native deployment practices.

ASAP start.

What We Are Looking For:

• Experience with backend development, preferably using Kotlin or Java
• Hands-on experience with Spring Boot
• Use of Kotlin coroutines and asynchronous/reactive programming
• Experience designing and implementing REST APIs
• Familiarity with OpenAPI (API-first approach)
• Experience with JWT-based authentication and security concepts
• Experience with PostgreSQL
• Writing unit tests and integration tests (Testcontainers)
• Understanding of cloud-native principles
• Experience working with Git and in an Agile environment

Nice-to-Have:

• Experience with reactive database access(Spring R2DBC)
• Experience building multi-tenant applications
• Experience with Docker and Kubernetes
• Experience creating Helm charts
• Familiarity with feature flags and production-readyCI/CD practices
• Previous experience working on SaaS or large-scale platforms

The collaboration is offered on a contractor basis (freelance or company-to-company).

The role includes occasional in-person meetings at our coworking space for project coordination, planning, and key milestones.

Zamestnanecké výhody, benefity:

Why come to us:

• Long-term product, not short-term outsourcing
• Real opportunity to influence architecture, technical decisions, and the future direction of the app
• A place where input and expertise are valued: we’re looking for a partner, not just task execution
  
• Local connection with purpose: Košice-based team and coworking space for coordination, workshops, and alignment