AWS/Azure/GCP, Kafka or other event-driven messaging technologies, Redis, NoSQL databases, API Gateway, OAuth2/JWT, OpenAPI/Swagger, Kubernetes/OpenShift, Jenkins/GitHub Actions/Azure DevOps, observability and monitoring tools such as Splunk, Dynatrace or Prometheus/Grafana, cloud-native development, distributed systems, and experience modernizing monolithic applications into microservices. Java/J2EE, Java 8/11/17+, Spring Boot, Spring Framework, Microservices Architecture, RESTful APIs, JSON, API integration, Hibernate/JPA, SQL, relational databases, unit testing, JUnit/Mockito, Maven/Gradle, Git, Agile/Scrum, design patterns, exception handling, logging, debugging, performance optimization, application security, Docker, Kubernetes, CI/CD, and DevOps practices.