... or more than 100 top French researchers for 3 years (Research Director, top pay at the end of the career is about 6000 euros / ~10000 for the company).

[source : https://fr.wikipedia.org/wiki/Directeur_de_recherche_au_CNRS ]

Note that this says "per expert". I'm not sure what exactly you'd consider an "expert", but I think a reasonable definition of "expert" could result in your average expert being a million-dollar-a-year engineer.

Does a thing like a million a year engineer exist?

I feel like this number would make more sense for a pool of researchers with a strong lead than a single person.

While I obviously don't know for sure, I'm quite confident that there are a nonzero number of employees at any very large Tech Company that are engineers (ie. do development work, commit nontrivial code), and whose compensation is over $1,000,000 USD. I doubt its common, and I would expect that many of those employees are not "just" engineers (ie. at the point where you are doing work that is that valuable, its almost a certainty that you are leading a team, and you are designing things), but I'm confident they exist.