Bridgewater Associates Technology Associate interview questions

I submitted my application for the Technology Associate position through Bridgewater's website and after about a week I received a coding challenge. The coding challenge was about a directed weighted graph and how it applies to Bridgewater. The problem was easy and I received a notice that they wanted to move forward about 2 days after I submitted my solution. Next came 2 phone interviews. The first was focused on seeing who I am and why I applied to Bridgewater. The second was technical and focused on the solution I sent. The technical call was a disappointment because the engineer I talked to obviously did not read my code before the call. We spent 45 minutes talking about how this problem was important to Bridgewater, nothing technical. After this call I received an email that they wanted to move to on-site. I setup dates and figured out when would be best to visit. Then randomly about 4 days later I received an email that they did not want to continue the interview process because all of their TA position were filled for the year. After spending hours taking coding challenges, phone calls, personality tests, and multiple interviews, I was rejected because HR couldn't figure out they had enough candidates already. Nice people, but really annoyed.