I found this reddit answer especially interesting, as it turns out it's the opposite of what you would expect. Soviet submarines were big on automation, had small crews (Alfa-class submarine – 30 people, vs 130 in a Virginia-class sub), and used lots of innovative design to make them quieter (sometimes redundantly – they were assuming the US would match Soviet capabilities in some aspects of sub detection, but that
still hasn't happened). What is more, they were much, much safer (in terms of crew survivability) and harder to sink, with a double hull design (as opposed to American single hull).
Part of the reason this worked this way was that the USSR had a number of fiercely competing design bureaus, while the US had a very centralized process with a very domineering research head. Quoting a Soviet designer: "We had competition in submarine design. You (with Rickover) had Stalinism!"
It's interesting how different this was from their aircraft design philosophy: https://www.reddit.com/r/WarCollege/comments/9abbo3/what_wer....
