My experience confirmed the negative impression conveyed by many of the other respondents here. This was easily the most bizarre thing that has happened to me in the course of looking for a job. I was asked in for an all-day interview and scheduled to talk to 7 people -- 3 in the morning, and 4 more after lunch. The morning interviews seemed to go ok, but at the end of the last one, the interviewer told me to wait in the room and someone would come to take me to lunch. They left me in there alone for almost 45 minutes, and finally an HR lady came in and told me they had decided to cancel the afternoon interviews and that I was no longer being considered! When I asked why, she said that they were looking for someone with more experience in a particular area. This raised some questions right away because 1) The area she mentioned was not even listed as one of the requirements of the job I was applying for, and 2) It happened to be an area that I had a great deal of experience and expertise in.
Of course this made me wonder what was really going on. I'm considerably older than most candidates, although well before retirement age. My resume lists only my last 15 years of experience, and no dates for my college degrees, so I suspect they didn't realize my approximate age when they invited me. Then I remembered that the HR lady who had greeted me in the lobby looked like she had just opened a bad Christmas gift, which I thought was odd because they usually try to be so bubbly and cheerful when greeting a candidate. And it's not like I came in wearing a t-shirt and sandals -- I had my best suit on, was well-groomed, polite, etc. I had never experienced any obvious case of age discrimination, but I can't think of any other explanation for the unprofessional, humiliating treatment I received. I certainly did nothing that would warrant being thrown out on my ear in the middle of the interview.
In view of my own experience and the many bad things I continue to hear about Masimo from other people I talk to, I would have to urge all but the most desperate (and young!) job seekers to stay away.
