ClickHouse An open-source, column-oriented database management system built for very rapid analytical queries (OLAP) over large volumes of data used heavily for real-time analytics, logging/observability pipelines, and dashboards. Contrast with row-oriented databases like MySQL/Postgres, which are better for transactional (OLTP) workloads.
WAS
Likely WebSphere Application Server — IBM's Java EE application server used to deploy and run enterprise Java applications. Common in large legacy enterprise environments (banking, insurance, telecom). If the context is different (e.g., a typo or something else), let me know and I can adjust.
Jenkins An open-source automation server used for CI/CD (Continuous Integration/Continuous Deployment) — automating building, testing, and deploying code. One of the most widely used tools in DevOps pipelines, highly extensible via plugins.
Kubernetes A container orchestration platform (originally from Google) used to deploy, scale, and manage containerized applications (typically Docker containers) across clusters of machines. Handles load balancing, self-healing, rolling updates, and scaling automatically. Core to modern cloud-native/microservices architectures.