Ask HN: How to prep for System Design interviews?

Hi HN,

I am assuming that most Software Engineers don’t get hands on System Design work in their day-to-day job, my questions are:

1. How to prep for System Design Interviews, given that most resources out there are very superficial in their explanation of what technology to use, when to use it and why to use it?

2. Will becoming good at prepping for System Design interviews actually help in designing large scale systems better?

3. If not 2, then how do you become better at designing actual systems?

I already know that DDIA is a good resource but it does not help you design concrete systems.