Pick a system. Work through the problem. Compare your approach.
Company tags are community-reported. Counts on cards show how many people reported that design.
Finding the nearby members of a set that is constantly moving. A table scan with a distance function is hopeless at any scale, and a stale position is worse than none — it sends a car to someone who left ten minutes ago.
The K most-viewed videos for the last hour, day, month and all time from 700,000 views a second, exactly and in milliseconds.
Radius, k-nearest and map-box search over places that rarely move and drivers that ping every few seconds: R-trees, geohash, H3 and S2 cells, Redis GEO and OpenSearch. One-hour boards for junior, senior and staff, with the theory.