Senior Java Engineer (#4350)

N-iX is looking for a Senior Java Engineer to join our team! Our client offers integrated telecom and cloud solutions, from carrier networks to UCaaS, and provides free assessments for communication needs.

Technical stack: Java 17+, Spring Boot (Web, Data JPA, Validation), MySQL/SQL, Maven/Gradle, Docker, Git, CI/CD (GitHub/GitLab), REST & OpenAPI/Swagger, Postman/Insomnia, basic Linux CLI.

Responsibilities:

• Implement backend features and own them end-to-end (planning → release).
• Design, document (OpenAPI), and maintain stable REST APIs.
• Maintain data models and migration strategies (MySQL + Flyway/Liquibase).
• Ensure performance and memory efficiency (profiling, query tuning).
• Build and maintain unit/integration tests (JUnit/Mockito/Testcontainers).
• Adhere to coding standards (reviews, static analysis) and ensure regression safety via CI.
• Provide release notes and short technical documentation.
• Define service interfaces, error handling, and retry strategies.
• Contribute to decisions between modular monolith and microservices.
• Ensure security (auth, permissions, input validation, secure defaults).
• Apply caching and messaging concepts (e.g., Redis, Kafka) where appropriate.
• Containerize services (Docker) and ensure CI/CD deployability.
• Establish logging/metrics/health checks; analyze and resolve incidents.
• Identify and reduce technical debt in a prioritized manner.
• Share knowledge (short docs, pairing, demos); communicate clearly with stakeholders.
• Integrate and test interfaces to devices/on-prem systems (e.g., local REST/MQTT).
• Consider networking aspects (HTTP, TLS, latency/time-outs, robust retries).

Requirements:

• 5+ years of experience as Software Development Engineer
• Strong proficiency in Java & Spring Boot
• MySQL/SQL including indexes, transactions, basic tuning
• Clean REST API design + OpenAPI documentation
• Docker, Git, CI/CD fundamentals
• Testing skills (JUnit/Mockito, integration tests with Testcontainers)
• Agile methodologies (Scrum/Kanban)
• Constructive code reviews and pairing collaboration
• English level — Upper-Intermediate+

Nice-To-Have

• Technical Skills: Spring Security (OAuth2/OIDC), Testcontainers, Kafka/RabbitMQ, Redis/caching, Flyway/Liquibase, Kubernetes/Cloud,
• Additional Qualifications: Oracle Java, Spring Professional, AWS/Azure basics
• Industry Knowledge in IoT/Embedded
• Education: Computer Science degree, Mathematics