QuestDB is an open-source, SQL-first time-series database built for the most demanding workloads—from trading floors to mission control. A multi-tier design keeps hot data in native partitions and cold history in Parquet/object storage, queried via one SQL layer. Vectorized, columnar execution delivers high-throughput ingest and millisecond queries. Open formats (Parquet/Arrow) make it AI-ready and lock-in free. Deploy self-hosted or in your cloud (BYOC).