Senior Software Engineer, Java

TENIOS GmbH

Senior Java Engineer building cloud communications and AI voicebot platforms at TENIOS. Developing scalable microservices, telephony integrations, Kubernetes deployments, and secure production systems in Cologne’s hybrid team.

Posted 8/11/2026full-timeCologne • 🇩🇪 GermanySenior💰 €67,000 - €72,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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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.

Highest-signal resume keywords

Java 21+/Spring DevelopmentMicroservices ArchitectureCI/CD ManagementCloud Platform Experience (AWS, Azure, GCP)Secure Development Practices

ATS Keywords

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Hard Skills

JavaSpring BootMicroservicesDockerKubernetesCI/CDObservability ToolsFreeSWITCHKamailioAI-Powered IVR

Soft Skills

Analytical ThinkingTechnical Decision-MakingIncident Response

Tools & Technologies

RabbitMQWebSocketsRTPGitHub ActionsGitLab CIJenkinsArgo CD

Certifications & Qualifications

ISO 27001 Compliance

Industry Keywords

Cloud CommunicationsTelecommunications ProtocolsCPaaSDistributed SystemsAsynchronous Messaging

Tech Stack

Tools & technologies

AWSAzureCloudDockerGoogle Cloud PlatformHibernateJavaJavaScriptJenkinsKubernetesMicroservicesRabbitMQSpringSpring BootSpringBoot

About the role

Key responsibilities & impact

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 FreeSWITCH and Kamailio
Implement ACD engines and AI-powered IVR workflows
Integrate real-time AI voicebot platforms via WebSockets/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

Requirements

What you’ll need

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 (GitHub Actions, GitLab 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

Benefits

Comp & perks

Gross annual salary of €67,000 to €72,000, depending on experience
Hybrid working model with a location in Cologne
An international B2B technology environment
Collaboration with customers across various European markets
Daily work with state-of-the-art AI solutions and digital tools
International, highly productive team with fast decision-making and tangible influence on the company’s growth