The HR called me about an opening which I was interested in, and he sent me a small assignment in Django to be completed online and uploaded to github. I did, and they were impressed. I was called in for an interview at their McLean, VA office. It was a pleasant experience. The HR spoke for a few minutes and then a senior technical person interviewed me. The interview was casual and tried to gauge the level of expertise I had in the subject. He also gave me a small bug to fix from a piece of software he was working on at that moment. It was a feel good interview. A couple of weeks later, I was called for another interview with the Head of Python Practice. He was more trying to sell their practice and make sure I liked their process and approach. I sure liked the way the discussion went. I met with another Department Head and he was trying to make sure I fit into their culture etc. Overall the interview process went great, although slow. They negotiated for a lower-than-market salary right in the beginning, but I thought it was a worth a try, so I agreed to it.
The HR was never responsive after the interview process. I had to constantly email him to ask about the status. A week later he replied saying we like you and we really want to have you on board with us, but we would like you to attend a client interview. At this point, I felt stupid because it felt like a company that does not stand by its employees. I agreed anyhow considering that the client was good. I still had not received an official offer, but at the client office, the client was told that I am a Celerity employee and I did not know how to react to that since I had not even received a verbal offer till that point. The client interview went ok, and I called the HR to let them know how it went. After this there was absolutely no contact from the HR whatsoever. It was a totally negative experience altogether. Waste of people's time and effort. If you do not want to hire a person or don't have an opening, please don't call candidates to attend interviews only to abruptly stop communications in the end.
My opinion - They seemed to me more like a body shop than a consulting company. So stay far away from this company. They lure you into giving an offer, and they talk well so we get impressed. But in the end, they don't care for their own people. I felt it was unethical for an IT consulting firm to attach your company logo to a person's resume to submit to a client before extending even a verbal offer to that person.
