InfluxDB is an open-source time series database (TSDB) developed by the company InfluxData. It is used for storage and retrieval of time series data in fields such as operations monitoring, application metrics, Internet of Things sensor data, and real-time analytics.
InfluxDB has been my go-to timeseries database for years, it is great at efficiently storing time series data, has nice integrations with one of the most used telemetry agents telegraf and is able to do some interesting queries, easily generating derivatives and moving averages.
Influx integrates very nicely with visualisation tool Grafana, which also sports an intuitive querybuilder to explore and visualise timeseries data.