I haven't followed mix panels development. I was surprised that a company which went as far as writing their own time series database apparently decided to go all in on Google cloud.
Disclaimer: Not the author, but I was on the team that migrated our infrastructure to GCP.
As a startup with limited resources, it's important for us to invest all our engineering strength into the things that create direct value for our business. We'd rather pay Google to manage machines and run services like Kubernetes, Spanner, Pub/Sub and others and free up the engineers to work on our core analytics platform.
I think the parent may have meant the opposite of how you interpreted it... That writing a tsd db from scratch doesn't match what you just stated about investing engineering time where it makes the most sense.
We don't run a TSDB. A TSDB doesn't work for the kinds of queries we run - specifically, TSDBs don't work if you want to
* analyze every datapoint you receive
* when the dimensional cardinality is high
* you want to analyze behaviors over time (e.g. the output depends on the orders of events followed - like creating a funnel report)
There's no off-the-shelf solution that does this at the scale at which we operate - hence the need to write our own custom solution.
