Great post. I was asked this question in an interview which I completely bombed, where the interviewer wanted me to think of flaky networks while designing an image upload system. I spoke about things like chunking, but didn't cover timeouts, variable chunk size and also just sizing up the network conditions and then adjusting those parameters.

Not to mention having a good UX and explaining to the customer what's going on, helping with session resumption. I regret it. Couldn't make it through :(