Tanium Sr Front-End Engineer interview questions

Initial interview with internal H/R recruiter, followed by an interview (video conference) with Engineering Manager. Next interview would have been online coding, but I was rejected after the video interview; so didn't proceed any further. The interviewer was 36 years old and I am substantially older than that. I got an email a couple days later stating they didn't feel my background fit their requirements, in spite of being a full-stack engineer for nearly 20 years and having worked six years in their industry of cybersecurity. I felt this was merely a pretext to legally exercise ageism.