Meta Software Engineer interview questions

1 phone screen + 4 interviews on-site

The talking was accompanied with noise. I was asked a simple string question. Because before the interview, the website recommend to give a solution which can be explained easily. I chose the simplest way to do so. And from the interview, I found facebook only want to get some programmer, but not researcher. Several days later, I got rejected. I think sometimes if you have time, you can choose some complicated algorithm, even you can not make sure to explain very well.