At a previous job I had to specifically accommodate the backend API design to slow, large-latency 3G links which much of our East Asian audience had at the time. South Korea is one thing, Malaysia, quite another.

Could you talk a little bit more about what changes you made on the back into accommodate that? That sounds interesting.

A lot of traffic still goes over 4G or even 3G in many countries. Most countries have only deployed 5G NSA (non-standalone) which means mobiles uses both 4G and 5G at the same time. Only a few networks in a few countries have deployed 5G SA (standalone) where mobiles use 5G only -- and even those few networks only deploy 5G SA in certain places e.g. selected CBDs. I live in the largest city in my country and I only get 4G still in my suburb and much of rest of my city is 5G NSA which means in most places phones stil use 4G for uplink and a mix of 4G and 5G for the downlink. Hence there is still a long way to go until most traffic (in both directions -- i.e. uplink AND downlink) is over 5G.