Druid Analytics

Apache Druid is a distributed, column-oriented data store optimized for real-time OLAP (online analytical processing). It ingests streaming events (from Kafka, HTTP) and enables exploratory analytics: "show me pageviews by country for the last hour" in sub-second latency. Architecture: ingest events → store in columns → index → query in parallel across nodes → return results in milliseconds. Designed for dashboards, monitoring, and alert systems.