As a large corporation SAP has 'companies within the company'. Your interview experience will depend upon which group you end up interviewing with (as each has it's own unique specifics).
As a company SAP generally looks for people with a specific vertical experience (i.e. Financial Services, Automotive etc). They also always prefer poeple who have some type of SAP experience (either as part of the partner ecosystem or direct experience as a customer etc).
Inteview process is relatively straightforward.
1. Phone screening from HR
2. Phone interview with hiring Manager
3. In person interview
4. Reference background check.
5. Offer/negotiation.
SAP generally will make a salary offer that is competitive BUT know what a job is worth since like any company if they can get you cheap they will.