1 Screening interview, 1 longer "real" interview, 1 full day at their office called "Assessment center".
The first two steps were pretty basic straight-line things. Nothing to really worry about, just practice like you would with an ordinary interview. Make sure that you can answer the "why" questions (Why did you choose Salesforce, why this position, why tech industry).
The Assessment center contained 3 interviews, split up between personal motivation for the job, Business Accumen and Cultural fit. It also had one business case where you had to present a solution together with two others. There's no crazy things happening, but make sure you have good knowledge on their big products and the company as a whole.
For the business acumen interview, try to think of what a sales rep need to know in a company. Why do the customers pay you, what do they want out of it. ROI and so on.
The cultural interview will be fine as long as you know their core values, and how you fit in with that.
The business case is mainly about showing that you can cooperate with people while being time-pressured, as well as knowing the products from a sales rep point of view. You don't need any programming knowledge, just more of what it can do to help companies grow etc.