Trellisware Technologies Software Engineer Embedded Linux interview questions

I thought the interview went well. I talked to 2 team leads and 2 staff engineers. The hiring manager, instead of spending lunchtime with me as planned, cut the interview short and said they had already made their decision. He showed me the door most unceremoniously. I have thirty years of experience as an embedded engineer, at a number of different companies. I have never been treated so shabbily at an interview that I thought was going well. Since they offered no explanation, I am assuming it is age discrimination. (I'm 64).