Computer Vision Interview Questions, issue 4, Jan 5, 2026

The L1 vs L2 Geometry Trap

Senior Computer Vision Engineer interview at Google, and the interviewer asks:

β€œWe’re building a similarity search for a new dataset. If I arbitrarily rotate the feature space by 45 degrees, which distance metric falls apart: 𝐋1 𝐨𝐫 𝐋2? And what does that tell you about our feature engineering strategy?”

Why rotating the feature space instantly exposes candidates who don’t understand metric invariance.

The full answer, with the mechanism and the arithmetic, is for paid subscribers on Substack.

Read it on Substack

Get the next one

Free on Substack. Unsubscribe in one click.