First off, let me say I was recommended to HR by a friend, so my experience may not be the norm. I started by emailing an HR representative for Mercury with my resume. HR responded quickly to my application and I immediately got a phone interview with a manager at the company. The interview was not technical, just asking about my resume and past experiences, the interviewer was clearly experienced and asked relevant questions. I was then invited to an on-site interview, where I went to Chelmsford and got to talk to multiple managers, a younger employee closer to my age, and an HR representative. The interviews again were not very technical, but they touched on many technical concepts. I did not have to answer any specific engineering "gotcha" questions and I was given plenty of time from each interviewer. I told them what area of engineering I was interested in and by the end of the day I was told I would be assigned to the manager that best fit my interests. Overall probably my #1 favorite interview process.