This sort of general architecture (store parquet-like files somewhere like s3 and build a metadata database on top) seems reasonably common and gives obvious advantages for storing lots of data, scaling horizontally, and scaling storage and compute separately. I wonder where you feel your advantages are compared to similar systems? Eg is it certain API choices/affordances like the ‘time travel’ feature, or having in-house expertise or some combination of features that don’t usually come together?

A slightly more technical question is what your time series indexes are? Is it about optimising storage, or doing fast random-access lookups, or more for better as-of joins?