Having spent time on both sides, I'll offer one pro-tip: Never comment on how difficult something should be. Just don't do it. Physically restrain yourself i

Having spent time on both sides, I'll offer one pro-tip: Never comment on how difficult something should be. Just don't do it. Physically restrain yourself if necessary from saying, "but it's only doing X, it shouldn't be that difficult." [1] If a smart technical person says that it's going to be hard, then it is going to be hard. If it really is a blocking issue for you, you instead need to bring your team into the bigger picture and ask, "At the end of the day, we're trying to solve a problem like X. How can we permute X into something we can solve more easily?" [1] Only if you are technical can you get away with this. You'll still be wrong if the other person has thought about it quite a bit more than you have, but at least you'll be able to understand and appreciate the explanation they'll throw back at you about what deep complication makes the problem hard.