As soon as you're making more than a few hundred grand, or you become a junior on a ladder that looks like you'll get there, people will get a hold of you on the personal side.
On the corporate side, as soon as you touch offshore, one of the big 4 that you already work with will suggest some tax optimization as a matter of course.
It's always weird, requiring whole pages of A4 diagrams, and you'll never really understand why these constructions work.
Some of the ones I've been offered have been downright ridiculous. One involved setting myself up as an advisor on rap lyrics. Another required me to publish my own poetry. IMO the weird ones are the most aggressive, and it's always sold as a tax reduction, so I've never gone ahead with them. It just seems too good to be true, and someone's gotta pay for social expenses.
On the corporate side, it's a bit less clear cut. You have a duty to shareholders to more or less do what everyone else does. There's also the fact that some governments actively court firms to set up shop with a discount, which is a sort of mutually beneficial bargain.