Crosswalk vintage arm-flip

temporal

Geolocation databases update weekly; a network block whose location estimate crosses an experiment arm boundary between releases flips every device behind it between arms mid-flight — differential contamination no deattenuation corrects.

Detection

Diff block→cell assignments across successive db vintages against the assignment partition.

Mitigation

Pin the db vintage for the assignment period
Re-pin only at period boundaries
Count, report, and exclude flipped blocks from analysis

Read the full article: IP Lookup To H3 →

Affected conversions

IP lookup → H3 (probabilistic crosswalk) approximate