I like both the questions for Technical I stick with my regular practice for developing mobile apps and it works they like my step-by-step ideas and solutions if the load or data increases then I change the data structure from Map to Class and all. For the System Design question I enjoyed most as I practiced a lot but they asked real-life scenarios for Mobile Apps so it challenged me to think better as I am a Mobile App so what can I develop for this and What will I need to think out loud and draw it on excalidraw. Communication is the key for all interviews they want to know what you're thinking and how you're trying to solve if you are stuck somewhere of course they will help by them self or you just need to ask for guidance because no one can develop a better product without team collaboration so showing collaboration with the interview as a team mates makes hugh impact as they feel that this is the person I want to work with future if you don't get whole answer still it will increase your chance. I did make a mistake during my Android Live Coding I didn't communicate well. All The Best for your interview :)