> "terrible technical decisions".
Another point worth bringing up is that sometimes, that stuff doesn't matter. I see so many engineers get hopelessly invested in technical debates that are, honestly, just silly: it's often better for the company to get something barely-good-enough done quickly than to flesh out the "optimal" design over the course of weeks or months, and over the dead bodies of people who have a different opinion about vi-versus-emacs.
And even if you accumulate tech debt, it is sometimes a wise decision to pay it back later, when you (hopefully) have more money and time.
So, I'd add "pick your battles wisely" to the list of tips.
Exactly my point of view. For the most part I do not root for my preferred technology, but rather try to inform my powers about the caveats I see. This way at least the right aspects to check have a chance to enter the debates above my payroll.