Hi all,

I'm new to this mikrotik world and would like to learn more
So, my boss asked me design a network for his coffee shop

1. the cafe would have some devices connected to the router through switch
2. there's also Access Point for backup just incase the LAN Cable is damaged
3. the cafe will a "free wifi" for customers spending their time there

several question, is it possible to setup a network topology like the drawing below?
if it's possible, what to set on the mikrotik?
and if it's not possible, is there any similar solution to the drawing?

Yes, that looks feasible, there are so many ways to configure this beast but a basic ether1 and ether2 cover off one subnet and ether3 and ether4 cover off a different subnet will work fine.
Note that there is a hotspot manager in RoS that may be perfect for the wifi hotspot to customers allocation and control. suggest reading up on it.