Where is fast matrix multiplication used?

Question

Algorithms

Tell me, please, what practical application do algorithms for fast matrix multiplication find (for example, Strassen's algorithm)? In what cases is the time spent on such calculations important? And where can I read more about it?
upd: I'm interested in cases where it is fundamentally important - 0.1 sec was spent on calculations or 0.2 :( Maybe somewhere in the military area, in navigation

Answer 1

Read about singular value decomposition (svd), today svd is used a lot in recommendation systems (news feeds / ad targeting / offers on movie services) in general, everything related to recommendations.
Strassen's algorithm can be applied in the initial stages of svd collapse