[giancarlostoro]

One thing that strikes me as foolish:

Giving an estimate without getting all cards on the table. If you have never touched the tech before, and it's new to all your engineers, and you don't invest time into figuring out effort and limitations, you will miss your estimate entirely.

Having an experienced developer evaluate parts of the projects is a good way to gauge the feasibility ahead of time. I went from one job that did this, to one that didn't, I'm back at the former as a result. You can't estimate work on things you've never done with technology that was birthed just yesterday, or lacks an open / public community.

To those PM's that estimate blindly I just want to say:

Good luck, we're all counting on you.[0]

[0]: https://www.youtube.com/watch?v=SmHeP9Sve48