Coding challenge pre-screen: some general knowledge multiple choice questions and 2-3 coding challenges, last one being the most difficult/time-consuming (I'd estimate it as LeetCode medium).
Phone screen: typical behavioral questions, technical experience, why you're looking at Vanguard, questions like "how have you handled disagreements with coworkers", etc.
Behavioral/technical interview: standard stuff, generally meant to gauge if you can fit into culture and to get an idea of how much experience you have under your belt. You are assigned a system design problem and given 30 minutes to draft a solution and explain your implementation and thought process. Some light technical questions, nothing extreme.