Sean Goedecke:

When a product manager says that something is critical, engineers generally have to shrug and say “sure, I guess”. This obviously requires a lot of trust. What’s a little less obvious is that this trust is continually broken by both sides. Every single product manager has been told thousands of times that technical task X is technically impossible or would be disastrous, only for that task to end up being done fairly smoothly and successfully. Every single engineer has been told thousands of times that requirement X is absolutely critical and worth going to enormous effort for, only for that requirement to be silently dropped or changed with no apology.