I see, thanks for your answer.

Do you implement your own storage with Quickwit or can it be backed by a cloud storage solution like S3?

I'm a cofounder of Quickwit and I did not use OpenReplay directly, I just know OpenReplay used ClickHouse + Quickwit for search. I don't know if this is a common setup and if it was just used for very specific use cases. You should ask them :)