I don't know the specifics, but we already collect the time people spend coding for productivity telemetry, so we already have that signal. I assume the team that maintains our chat system either hooks into an editor notification, or into the Kafka-like event queue that feeds into the data warehouse. It likely only works if you're using the officially blessed IDE, but very nearly everyone does
That does sound Kafkaesque, but maybe it's a weird example where intrusive surveillance isn't completely bad.
The actual non-anonymized data is closely guarded to make sure that nobody gets any funny ideas about mistaking it for actual performance measurement!