Why Page Weight Matters

Here is a fascinating story about a web developer at YouTube, and their quest (code named “Feather”) to reduce the overall download sizes of their video pages. What seems at first to be a fairly straightforward exercise in bandwidth reduction took a surprising turn, and ends up having a surprising lesson regarding mobile first design:

After a week of data collection, the numbers came back? and they were baffling. The average aggregate page latency under Feather had actually INCREASED. I had decreased the total page weight and number of requests to a tenth of what they were previously and somehow the numbers were showing that it was taking LONGER for videos to load on Feather. This could not be possible. Digging through the numbers more and after browser testing repeatedly, nothing made sense. I was just about to give up on the project, with my world view completely shattered, when my colleague discovered the answer: geography.

I won’t spoil the ending for you, because what they found is rather surprising. I’m sure you’ll be able to draw the implications regarding mobile design.