Sometimes it’s so easy in Photoshop to re-design an app screen and change the size of an element:
"Look at those teeny avatars! Wouldn’t it be better to make them 30px high instead of a measly 25px?" And with a quick drag of the transform tool, your design is more beautiful and you go home happy…
Until engineering wants to shoot you. As it turns out, all those measly little avatars have been stored in S3 at 25px and your quick resize means that someone needs to run a script and resize all 3 million of them. Small task? Maybe, but depends on how many to-do’s are on their plate.
Luckily, the backend for the app that I’m helping is clean enough that engineering can get it done with minimal effort, but I’m glad that I caught that implication and got engineering go-ahead before going home happy or digging my heels thinking that 30px is the way it HAD to be.