There were constant red flags throughout the entire process. All HR employees that I had contact with behaved questionably and demonstrated unprofessionalism including constant rescheduling, citing unconfirmed availability with main interviewer, contacting candidates directly instead of through the 3rd party recruiting agency (goes against common process and client/candidate agreement), disparaging comments about other departments and employees, describing dire inefficiencies and abusive work schedules, and HR personnel have unprofessional and questionable internet and social media footprint. Company demands thank-you letter or you won't be considered yet doesn't display equally expected standards of quality communication or professionalism.