What is time-series data, and why are we building a time-series database (TSDB)?

Like all good superheroes, every company has its own origin story explaining why they were created and how they grew over time. This article covers the origin story of QuestDB and frames it with an introduction to time series databases to show where we sit in that landscape today. Time series is a succession of data points ordered by time. These data points could be a succession of events from an application's users, the state of CPU and memory usage over time, financial trades recorded every microsecond, or sensors from a car emitting data about the vehicle acceleration and velocity. For that reason, time-series is synonymous with large amounts of data.