Me, writing a webpage for cat pictures:
* Is the result in the server's L3 cache?
* Will the user's ambient lighting affect perceived color temperature?
* Is latency harmed by Nagle's algorithm?
* Will showing these cats badly impact democracy?
* How to center this div??
100% there should be no such thing as a front end developer outside of super junior contexts. All developers need to think across all the layers that they build on to be effective.