The process took about three months. There were two interviews and a fairly easy test. The interviews were lengthy, detailed-oriented, and involved multiple people. Everyone was friendly and courteous, but the company clearly takes great care to ensure that they are getting someone who will be able to do the job and be a good fit with existing staff.
I had no interaction with HR until the offer was being prepared. Invensys HR uses multiple online systems to collect various types of information from applicants and new employees, for recruiting/application, background check, and onboarding. These systems don't share information between them, so you have to enter the same information again and again into the different systems. It is very time-consuming and somewhat irritating, but not unusual.