I completed the Meta E4 Full Loop for Software Engineer, Machine Learning and received an offer. Here you have the process:
Phone screen
Full Loop
Performance in Full Loop
I did well 3/4 coding challenges. Was not able to complete 1 of them. The behavioral and ML System Design rounds went well. I thought there was not going to be an offer, as I wasn't able to complete one of the coding questions, even with brute force.
My advice
Be communicative, explain your thought process and try to do your best. They are looking for a good fit for the company, not someone that can perfectly solve all the problems. Good luck!