A couple of rounds—first with an ISSI employee, then 1-2 rounds with the customer/client. Your results may vary (wildly) on the latter, as it's outside of ISSI's control. In my case, the end client was a certain gigantic government agency, and ISSI was a subcontractor, so I was interviewing with the contractor (Leidos). They were kind of unorganized, but that really comes down to the Leidos manager assigned to the account. Mine was OK, but it was clear that my IT sub-specialty was way above her head, so she didn't really know the best questions to ask. Worked for me, because I got the job.