QuestDB
Time-series database with Postgres wire and SQL — designed for financial tick data and IoT. Tracking data + InfluxDB Line Protocol support.
Nikolay Romanchin + Vlad Ilyushchenko founded 2014. YC batch 2020. Big benchmarks show 3-10× faster than InfluxDB/TimescaleDB. Columnar storage + nanosecond timestamps. Big customers: financial trading firms, Toyota. Competitors: InfluxDB, TimescaleDB, ClickHouse (also good at TS).