Senior Java Developer IoT

Our goal is to develop a product that integrates with the ecosystem of various eSIM services. We provide an "entry point" that is a consistent and comprehensive set of services that enable the customer easily and transparently manage his eSIM devices. Our clients include mobile network operators, car manufacturers, payment terminal providers and many others.

You will be working on a real IoT platform, where backend services communicate with devices and cloud components. The system processes asynchronous, event-driven data flows, handles unstable connectivity, and runs in a cloud-native, containerized environment.

The project includes:

• device ↔ backend ↔ cloud communication,
• event-driven and asynchronous processing,
• cloud-native deployment,
• scalability, reliability and observability,
• security mechanisms based on encryption, certificates and credentials,
• containerized environments.

• Strong, hands-on experience with Java 17 / Java 21
• Commercial experience with Kotlin
• Proven experience in designing and developing backend systems for distributed environments
• Deep understanding of asynchronous and event-driven architectures
• Ability to design clean, maintainable and testable codebases
• Experience working with code reviews, technical leadership and mentoring
• Strong understanding of system reliability, scalability and fault tolerance
• Experience with Spring ecosystem (Spring Boot, WebFlux)
• Experience with Docker and containerized applications
• Experience with Kubernetes (designing and operating services in k8s)
• Experience with Git / Bitbucket workflows
• Experience with CI/CD pipelines (Jenkins)
• Experience with Azure cloud environment
• Knowledge of cloud-native application design principles (12-factor app)
• Experience with relational databases (MySQL, MariaDB)
• Knowledge of security fundamentals (TLS, symmetric / asymmetric cryptography, secrets management)

Nice to have:

• Experience with IoT platforms or large-scale distributed systems
• Experience with messaging systems (Kafka, RabbitMQ, MQTT)
• Experience designing event-driven and eventually consistent systems
• Knowledge of cloud architecture patterns
• Experience with Camunda or other BPMN / workflow engines
• Experience collaborating closely with QA and DevOps on quality and automation

• Design and evolve backend architecture for IoT systems
• Implement complex, business-critical backend components
• Make architectural and technical decisions within the team
• Ensure system scalability, reliability and security
• Review code and mentor Regular and Junior developers
• Collaborate closely with QA engineers on test strategies and E2E scenarios
• Actively contribute to CI/CD and deployment strategies
• Support troubleshooting of production issues and root-cause analysis
• Work closely with architects, product owners and team leader