Do Sephardim soak the meat before salting as do Ashkenazim?

Yes.

Explanation: According to the Michaber, there is no obligation to soak the meat for any specific amount of time, but it rather suffices to simply rinse it well. This is because the Michaber does not suspect for the opinion of the Ran which requires Hadacha Rishona to be performed in order to soften the meat. Alternatively, the Michaber holds that rinsing the meat also softens it and soaking is unnecessary. [See Peri Megadim Hakdama] Nevertheless, it has become the accepted custom even amongst Sephardim to soak the meat before the salting and so is done by all the Sefaradi Hashgachas.

Sources: See Michaber and Rama 69:1; Hakashrus 9:57