Can an employer arrange for a foreign specialist he needs without putting in a lot of effort?

Question

Law in IT

It is no secret that many employers often do not want to legally register foreign citizens on the territory of the Russian Federation. But this applies to those who work on construction sites and make any repairs.
So, given:
- A stateless (IT) specialist who completely suits the employer
- The employer is interested in him, and gave preference to him, and not to other candidates
- The city is not Moscow, but Voronezh
Questions:
- What will the employer need for registration? In particular, they are interested in terms and the budget spent on his part.
- Maybe it will be easier in terms of time and resources, first to get him citizenship of the Russian Federation, and then to apply for it?