Use Case Design Question

I’m working on putting together a solution for a use-case and I wanted to reach out to the community to make sure that I’m going down the right path.

The use-case is for tracking how long a person is in line. For example, say you’re at a grocery store register. There’s a sensor that detects when you enter the register lane. This sensor will record when you arrive and when you leave. I also have a data source (different from the sensor) on when you complete your transaction. The goal is to have realtime stats on each register lane and the averages for how long someone is in the register lane and the average time from when you enter to when the transaction completes.

I’m thinking that Druid can accomplish most of my goals, the averages, but since this is more binary states (on or off) with timestamps, I’m having a hard time getting my head wrapped around it. I’m probably trying to overcomplicate it in my head.

Thank you!