Vital Connect interview questions

Interview arranged with the VP of Software Development and with 3 of the 4 members of the team. Was asked to white-board a database solution for a complicated problem, and asked about Ruby / Java concepts and scalability concepts. The entire affair lasted about 3 and a half hours, and the questions were quite pertinent to the job. I appreciated that the common 'gotcha' questions were avoided, which tend to test how good a candidate is at interviewing rather than their strengths for the specific position.

I submitted a resume online, heard back from their HR VP two business days later, had a <15 minute phone screen with the hiring manager (director of IT) the next day, then came in for an onsite interview less than a week later. They moved pretty quickly. The onsite interview was with three sets of two people, totalling two and a half hours. The hardest technical questions anyone asked were rudimentary unix command line usage questions. To me, this is a red flag -- if they don't ask me hard questions during the interview process, they probably weren't very rigorous when interviewing my prospective future coworkers, either. It also sounds like they've developed a cool piece of technology, with a laundry list of problems they think it could potentially be used to solve, but haven't really produced a solution to anything (compared to, for example, AliveCor, which is also in this space, but more targeted). Where's the business model? Technology on its own is not enough! At the end of the interview, the hiring manager told me to expect to hear back from their HR VP at the end of the following week. I was not contacted in their time frame. I tried to contact them by email, but received no response (even a month later). I've never had a prospective employer fail to follow up after an onsite interview; this makes them look staggeringly unprofessional. If they can't treat potential employees well during the hiring process (when they should be trying to make a good impression), then how will they treat you after they hire you?