Senior Software Engineer, Java

• Take end-to-end responsibility (“you build it, you run it”) for the cloud-native communications platform
• Develop and maintain low-latency call-control systems using Free SWITCH and Kamailio
• Implement ACD engines and AI-powered IVR workflows
• Integrate real-time AI voicebot platforms via Web Sockets/RTP
• Evolve and scale the Java 21+/Spring-based backend platform with microservices and RabbitMQ
• Expand multi-tenant capabilities and maintain usage-rating, billing, and invoicing engines
• Apply secure-coding practices to support ISO 27001 and NIS 2 compliance
• Manage CI/CD pipelines, Kubernetes deployments, and observability to achieve 99.99%+ availability
• Maintain existing Backbone.js and Marionette.js frontends and lead the migration to modern frontend frameworks
• Adopt and promote AI-assisted development tools and agent-based CLI workflows
• Work closely with Platform Engineering, Security, and Product teams

• Minimum of 5 years of professional software development experience with a strong focus on Java-based backend systems
• Solid knowledge of modern Java (17/21+), Spring Boot, Spring Framework, JPA/Hibernate, and RESTful API design
• Experience designing and implementing distributed, cloud-native applications with microservices
• Hands-on experience with Docker, Kubernetes, and at least one modern CI/CD tool (Git Hub Actions, Git Lab CI, Jenkins, or Argo CD)
• Experience with at least one major cloud platform (AWS, Azure, or GCP)
• Strong foundations in automated testing, code reviews, and CI/CD practices
• Good understanding of secure development practices (OWASP Top 10, dependency and secrets management)
• Experience with observability tools for metrics, centralized logging, distributed tracing, and APM
• Confident operating production systems and participating in incident response
• Strong analytical thinking and sound technical decision-making in complex distributed systems
• Fluent English, both written and spoken
• German language skills are a plus
• Experience with AI-assisted development tools or openness to using them
• Experience with CPaaS or cloud communications platforms, telecommunications protocols, or related open-source frameworks is a plus
• Knowledge of carrier-grade, highly available, low-latency distributed systems is a plus
• Experience with asynchronous messaging or event-driven architectures is a plus

Demonstrates expertise in developing and maintaining cloud-native communications platforms, with a strong focus on Java 21+/Spring-based backend systems and microservices architecture. Proficient in secure coding practices, CI/CD management, and observability tools to ensure high availability and compliance.

• Java 21+/Spring Development
• Microservices Architecture
• CI/CD Management
• Cloud Platform Experience (AWS, Azure, GCP)
• Secure Development Practices

• Java
• Spring Boot
• Microservices
• Docker
• Kubernetes
• CI/CD
• Observability Tools
• Free SWITCH
• Kamailio
• AI-Powered IVR

• Analytical Thinking
• Technical Decision-Making
• Incident Response

• ISO 27001 Compliance

• Cloud Communications
• Telecommunications Protocols
• CPaaS
• Distributed Systems
• Asynchronous Messaging

• RabbitMQ
• Web Sockets
• RTP
• Git Hub Actions
• Git Lab CI
• Jenkins
• Argo CD