Then you ask a PM for specs before you start, or at least a brief with what needs to be done, and maybe a rough planning based on estimates and not what the customer said what are the deadlines, and they get really offended.

Yes, it’s fun when you make an estimate and planning for the lastest sale and it turned out the three weeks sold is three months of work. No, I don’t care what you promised, it’ll be ready in three months. Ask for an estimate before you make that promise next time.