> I've gone through times when management would treat estimates as deadlines, and were deaf to any sort of reason about why it could be otherwise, like the usual thing of them changing the specification repeatedly.

I worked at a place where this management insanity was endemic, which lead to everyone padding all estimates with enough contingency to account for that. Which lad to the design team, and the front-end team, and the backend team, and the QA team, all padding out their estimates by 150 or 200% - to avoid the blame storms they'd seen for missing "deadlines".

Then the Project managers added those all ups and added 150 - 200%. Then the account managers and sales teams added 150 - 200% to the estimated costs before adding margins and setting prices.

Which ended up in literally around 1 million dollars a month to maintain a website which could _easily_ have been handled by a full time team of 8 or 10 decent web and full stack devs. Hell, apart from the 24x7 support requirement, I reckon I know a few great Rails or Django devs who could have done all the work on their own, perhaps with a part time of contracted graphic designer.

That all lasted a handful of years, until the client worked out what was going on, and my company management flew the whole thing into the mountain, with ~100 people losing their jobs and their owed entitlements (I was out about $26K that day.)