Senior Software Engineer (Java) – Cloud Communications (m/f/d)
Senior backend engineer designing and running Java 21+/Spring Boot microservices for Apifonica's cloud communications (CPaaS) platform. Owns services end to end on Kubernetes with CI/CD, observability and secure development practices, working hybrid from central Warsaw.
- Compensation
- PLN 21K–PLN 25K / mo
- Location
- Poland
- Work setup
- Hybrid
- Seniority
- Senior
- Employment
- Contract
- Experience
- 5+ years
- Category
- Software engineering
- Posted
Skills
Must have
- 5+ years of professional software engineering experience with a strong focus on Java-based backend systems
- Strong knowledge of modern Java (21+), Spring Boot, Spring Framework, JPA/Hibernate and RESTful API design
- Experience designing and implementing distributed, cloud-native applications using microservices
- Hands-on experience with Docker, Kubernetes, and at least one modern CI/CD tool (e.g. GitHub Actions, GitLab CI, Jenkins, Argo CD)
- Fast learning curve with a track record of adapting to changing tech stacks
- Solid grounding in software quality practices: automated testing, code reviews, CI/CD
- Good understanding of secure development practices (OWASP Top 10, dependency & secrets management)
- Experience with observability tooling: metrics, centralized logging, distributed tracing, APM
- Comfortable operating production services and responding to incidents
- Strong analytical thinking and sound technical decision-making in complex distributed systems
- Fluent in English (written and spoken)
- Practical experience using AI-assisted engineering tools (e.g. Claude Code, GitHub Copilot) or genuine openness to adopting them
Nice to have
- German language skills
- Experience with CPaaS or cloud communications platforms, telecom protocols (SIP, RTP, WebRTC), or related open-source frameworks (FreeSWITCH, Kamailio, Asterisk)
- Familiarity with carrier-grade, highly available, low-latency distributed systems
- Experience with asynchronous messaging / event-driven architectures (Kafka, RabbitMQ)
Full description
Design & build
- Design and implement backend services and APIs in modern Java (21+), Spring Boot and related frameworks
- Build distributed, cloud-native applications using microservice architectures
- Work with container technologies (Docker) and Kubernetes, and collaborate with Platform Engineering on infrastructure-related changes
- Contribute to CI/CD pipelines and deployment automation
Ship & operate
- Own services end to end following a “you build it, you run it” mindset — including monitoring, logging, troubleshooting and incident response
- Use observability tooling (metrics, centralized logging, distributed tracing, APM) to keep services healthy in production
- Apply secure software development practices, including OWASP Top 10, dependency and secrets management
Collaborate & improve
- Work in Agile product teams (Scrum/Kanban) with a collaborative, ownership-driven mindset
- Review code, mentor colleagues, and help raise engineering quality across the team
- Use AI-assisted engineering tools where useful to speed up delivery without compromising quality or security
Important to know
- You will own services end to end. From design through to running them in production
- Cloud-native and DevOps skills (Kubernetes, CI/CD, observability) matter as much as core Java expertise
- You will work closely with Platform Engineering, Security and Product — this is a collaborative, not a siloed, role
- Our domain is telecommunications and cloud communications, so telecom background is a strong plus but not a requirement
- We use AI-assisted engineering tools as part of our normal workflow and expect openness to them
- 5+ years of professional experience in software engineering with a strong focus on Java-based backend systems
- Strong knowledge of modern Java (21+), Spring Boot, Spring Framework, JPA/Hibernate and RESTful API design
- Experience designing and implementing distributed, cloud-native applications using microservices
- Hands-on experience with Docker, Kubernetes, and at least one modern CI/CD tool (e.g. GitHub Actions, GitLab CI, Jenkins, Argo CD)
- Fast learning curve with a track record of adapting to changing tech stacks
•
- Solid grounding in software quality practices: automated testing, code reviews, CI/CD
- Good understanding of secure development practices (OWASP Top 10, dependency & secrets management)
- Experience with observability tooling: metrics, centralized logging, distributed tracing, APM
- Comfortable operating production services and responding to incidents
- Strong analytical thinking and sound technical decision-making in complex distributed systems