java developer in cloud-native solutions

Callisto Web Solutions B.V. provides IT services and consulting, delivering cloud-native solutions for clients.

• Design, plan, and implement microservices-based architectures across the full software development lifecycle;
• Develop scalable and maintainable applications using Java 17/21 and Spring Boot 3;
• Design and implement event-driven architectures using Kafka and Azure Event Hubs;
• Develop secure applications using OAuth2, JWT, and Spring Security;
• Work with SQL and NoSQL databases, including Azure Cosmos DB;
• Analyse and optimise application performance through JVM configuration, profiling, garbage collection, and performance tuning, including JMeter;
• Develop and maintain comprehensive unit and integration testing using Mockito, Testcontainers, Rest Assured, and Cloud Contract;
• Build and manage containerised applications using Docker and Kubernetes, preferably Azure Kubernetes Service (AKS);
• Implement and maintain CI/CD pipelines and cloud-native deployment practices;
• Design and manage Azure infrastructure using Infrastructure as Code with Bicep/Terraform;
• Implement and maintain Azure security practices, including Identity Management, RBAC, and compliance;
• Develop monitoring and observability solutions using Azure Monitor, Prometheus, and Grafana;
• Identify opportunities to improve resource utilisation, performance, scalability, and cost efficiency;
• Stay up to date with emerging technologies and contribute to continuous technical improvement.

• Extensive professional experience with Java 17 and/or Java 21;
• Strong experience with Spring Boot 3 and the Spring ecosystem, including Spring Core, Spring Security, Spring JPA, Transactions, and AOP;
• Strong understanding of microservices and distributed systems;
• Experience with SQL and NoSQL databases, preferably Cosmos DB;
• Hands-on experience with JVM performance tuning and memory management;
• Experience with OAuth2 and JWT;
• Practical experience with Kafka and/or Azure Event Hubs;
• Strong experience with Docker and Kubernetes, preferably AKS;
• Solid knowledge of Microsoft Azure, including Key Vault, Storage, VMs, Networking, and related services;
• Experience with Terraform and/or Bicep;
• Knowledge of cloud security, identity management, RBAC, and compliance;
• Experience with Azure monitoring, Prometheus, and Grafana;
• Strong understanding of CI/CD and DevOps practices;
• Excellent problem-solving, communication, and collaboration skills;
• Ability to work effectively with clients and multicultural, multidisciplinary teams.

• No conditions specified