In the architecture of heavy-duty business programs, customer relationship management software is a load-bearing beam. It’s a mission critical application that can be a key to success. It’s also the sort of app that operates very comfortably in “the cloud” — that metaphor for the Internet and platform-agnostic computing. Justin Bartak realized the cloud’s potential for managing customers relatively early. Bartak is CTO and cofounder of Ntractive, a Grand Folks, N.D., Macintosh-centric CRM software maker.