[lortex]

Thank you ! It's indeed precomputed levels of detail, the backend serves a key-value store: for each bucket a top 10 events that start or end in this bucket. A bucket is described by its zoom level (from 1 day to 2^34 days) and time coordinates.

[keynha]

Makes sense, thanks. The fixed 10-per-bucket cap is what keeps every viewport the same size no matter the zoom, that's the elegant bit.