DataStax Software Engineer interview questions

Standard interview process consisting of a phone call from a recruiter followed by multiple tech interviews via video conferencing. They will give you a programming problem to solve in your language of choice. I solved the programming problem only to have it labeled as too simplistic of a solution. Evidently the hiring manager made a mistake in not providing a challenging enough problem to solve. I was asked to solve a more difficult version of the problem after which I decided to halt the interview process. I deem this behavior as unprofessional and a complete waste of a candidates time. It looks like DataStax is a young company - unfortunately many of their managers lack professionalism and good interview etiquette. Some of the negative reviews from existing employees confirm this. This appears to be a case of a company promoting engineers to management roles without providing them management training.