I felt Facebook in invested at a very large scale on interviewing. Very well structured process. The recruiters are great and really helpful resources during the process. They spend a lot of time to answer questions and getting help. I had opportunity to informally talk to an EM to answer questions about interview, tips on approaching the probelms. They do biweekly mock interviews which was very helpful to attend and see a live interview to get an idea on how to approach system design questions. Most of the questions asked for management rounds are given in the sample questions asked. Overall, tons of resources facebook provides to prepare for the interview.
In terms of succeeding, i suggest really practicing on whiteboard ( on excalidraw even better ) typical system design questions you find online, design instagram, netflix, uber types system and really follow the format clarifying functional requirements and non functional requirements before jumping into the solution.
Management rounds i really to reflect your own experience, i suggest to structure your thoughts around on your experience in a way so that you try to provide as much signals as you can in your answers.
Coding round was definitely a bit more challenging but practicing on leetcode helps.