Hi there,

I've been searching for some information related to what a mobile iOS/Android onsite system design interview is like at a FAANG type comany. I haven't really found much information accept, "How would you design the Twitter app?".

I'm looking specifically for anyones experience or any guides that can prepare for this. When searching for this information I mainly find what a fullstack/backend engineer system design interview would be like, with topics related to load balancers, cloud (AWS,GCP,etc), distribution related things, which doesn't apply to mobile.

I assume, mobile would be something along the lines of designing an app architecture with several layers, UI/service/db stuff, but I haven't found that confirmation.

One of the examples I was told was "Design a restaurant reservation app". Well thats great and all what are the steps I would take to do so in an interview environment which would be 1 hour long?

From what I've gathered, that means:

1. Gather requirements (inquire about product features, really anything product related)
2. Then start to whiteboard some diagrams (my question is diagam what?)
3. Talk about implementations (what does that really mean? should I be talking about how the layers interact with each other, should I be talking design patterns like MVVP/VIPER, or maybe something else?)

My question specifically, if someone were to ask you to whiteboard an app architecture, what would you do? Where would you start? What would you draw, what diagrams are useful for this situation?

If it is like this, how do I prepare for it? If anyone could provide any resources that could help answer my question, that would be appreciated.

Thanks.