I'm curious if this is built on top of ClickHouse (https://blog.cloudflare.com/http-analytics-for-6m-requests-p...) or if you're using something else behind the scenes?

Yep, we use ClickHouse! And a lot of other software :)

interesting.. would simplify a lot for us, especially if retention would be scalable or at least data would be exportable from clickhouse.. unclear in the article Hope this will not be an Enterprise only thing (we can't afford that) but priced similar to workers