Increase in Known Faces consider rate

## Summary

On August 26, 2026, an increase in the consider rate of Known Faces was observed during the period between 15:00 and 18:00 UTC. The overall observed consider rate of Known Faces increased from ~6% to ~23% across all regions. Perceived increase may have been higher or lower, depending on the client’s specific geography or vertical.

The was driven by a change to how matching scores are calculated for Known Faces matches, which inflated scores for non-matching faces and thus causing many reports to return false matches and a **consider** result.

## Root Causes

The change introduced a new algorithm for scoring matching faces, which is intended to improve Known Faces recall performance. This was extensively evaluated and validated by internal benchmarks before being released. Inadvertently, the transition from benchmarks to production partially failed to account for particular production environment characteristics. At the root, a single constant wasn’t properly converted in the transition, resulting in wrong behavior of the new scoring algorithm.

## Timeline

    15:20 UTC: Change to Known Faces is released
    17:35 UTC: Increased consider rate on Known Faces is noticed.
    17:50 UTC: Change is rolled back. Consider rate drops soon after.

## Remedies

We are reviewing internal benchmarks and testing procedures which can increase the safety of this kind of change. Specifically, ensuring internal testing reflects the real production landscape when it comes to datasets and that transitions from internal benchmarks and experiments to production are thoroughly tested.

In addition, change procedures will be carried out with tighter monitoring so it allows us to notice and act faster.

Known Faces experiencing higher consider rates across all regions.