Fidelity Investments Senior Software Engineer interview questions

I applied online. The process took 2 weeks. I interviewed for Fidelity Investments (Boston, MA) in July 2020. I had 3 online interviews (zoom): 1 with a principal engineer who asked me a parentheses matching coding problem. Asked a bit about my current role and responsibilities. (45 mins) A week later, after getting through the initial technical round, I had two 1 hour back to back coding sessions with a Senior Software and Principal Engineer and another one with a Senior Software and Software Engineer. Both were purely technical, In the first round, they asked me group of anagrams sorting problem. In the second row, they asked me wrong way cow problem. I was able to solve group anagram but my complexity is O(n)2. The interviewer was not really helpful or encouraging in anyway. He was a bit harsh. I partially implemented the wrong way cow problem. (not enough time as 15min in 45mins were spent talking about my current role and responsibilities)

I applied online. The process took 3 months. I interviewed at Fidelity Investments Dublin, Dublin in May 2020. I had two rounds of interview. First round was Hire View interview and the second round was video call with team managers. The recruitment process is very long and they don't give any feedback.