Senior Java Backend Engineer — Cloud Microservices

SmartTel Plus OÜ; Warszawa; On-site; PLN 234,000 - 279,000; Full time

Benefits offered by this job

Compensation: 21,000-25,000 PLN net +税

Hybrid working model in Warsaw center

Private health insurance

Sports card

International tech environment

AI-focused technology

Influential team

Job summary

Apifonica seeks a senior Java backend engineer to design and build cloud-native microservices using Java 21+, Spring Boot and related frameworks, Docker and Kubernetes. Own services end to end, contribute to CI/CD, observability, security (OWASP Top 10) and incident response in a telecoms/cloud communications domain; collaborate with Platform Engineering and Product in an Agile setup.

Hybrid Warsaw center; 21,000–25,000 PLN net + VAT per month (B2B) depending on experience; private health

Qualifications

• 5+ years of professional software engineering experience with Java backend systems.
• Strong knowledge of modern Java (21+), Spring Boot, RESTful API design.
• Experience designing distributed, cloud-native applications using microservices.
• Hands-on experience with Docker, Kubernetes and CI/CD tooling.
• Security-focused with OWASP Top 10, dependencies and secrets management.
• Fluent English; German is a plus.
• Experience with observability tooling and incident response.

Responsibilities

• Design and implement backend services and APIs in Java 21+ with Spring Boot.
• Build distributed, cloud-native applications using microservices.
• Own services end to end including monitoring, logging and incident response.
• Collaborate in Agile teams, review code and mentor colleagues.
• Apply AI-assisted engineering tools to speed delivery while preserving quality.

Skills

Java 21+

Spring Boot

Microservices

Docker

Kubernetes

CI/CD

Observability

Security mindset

English (fluency)

Tools

GitHub Actions

GitLab CI

Jenkins

Argo CD

Terraform

Job description

Apifonica seeks a senior Java backend engineer to design and build cloud-native microservices using Java 21+, Spring Boot and related frameworks, Docker and Kubernetes. Own services end to end, contribute to CI/CD, observability, security (OWASP Top 10) and incident response in a telecoms/cloud communications domain; collaborate with Platform Engineering and Product in an Agile setup.

Hybrid Warsaw center; 21,000–25,000 PLN net + VAT per month (B2B) depending on experience; private health