The reason the san fran interview tends to focus on theoretical cs more so than other regions is because the plethora of berkeley and stanford grads in the area

The reason the san fran interview tends to focus on theoretical cs more so than other regions is because the plethora of berkeley and stanford grads in the area, who subconsciously prop the entirety of their ego on their college educations, and thus use it as a measuring stick for others, sometimes at the cost of a good, practical hire. I've seen job descriptions for FRONT END positions which list a cs degree as a 'must,' which is just absurd in today's day and age.