Two remaining interviews with Datadog

I finished first phone-screen coding round, react coding and algorithm coding rounds. They all went well. With remaining two rounds of system design and behavioral scheduled in about 1 week, what tips would you give me to make the most of those two interviews? I am trying to get hired at staff level position and therefore, taking my time in preparing for system design interviews. My profile: 20 yrs experience as team lead and frontend engineer #datadog #staff #sse #software #engineering @Datadog