We had enough email exchanges to establish my abilities and moved to multiple phone interviews with the actual managers I would be working with if hired. About a month after the process began they invited me to California for a live interview and tour of the facilities.
The company provided lodging and a rental car for my two day stay and covered all other transportation costs through a simple reimbursement account with Wells Fargo.
Though I only had one interview in person, the candidate who eventually landed the job said that he had several more interviews before being offered the job.