Mazepin is whats known as a 'Pay Driver'. They bring along the sponsorship and fund the team so the deal is quite lucrative. It doesn't guarantee talent.
Mazepin had some success in F2 but had a reputation for being quite dangerous and he punched Callum Illot.
Haas F1 had a a checkered history with sponsors so when Daddy Mazepin came along, who owned a Russian company called Uralkali and was good mates with Putin, they jumped at the chance to put him in the car and take the cash, running pretty much under a poorly disguised Russian flag livery.
Before the start of the last season Mazepin was in trouble again, this time for sexually harassing a girl. A video was posted and what followed were screen shots of other messages from young female fans who's been hit on by him and asked to attend races. Fans were not happy and pressured Haas to replace him, but money talks in F1 so he kept his seat.
His start was shaky. His first GP lasted 20 seconds and he quickly became christened 'Mazespin' because he couldn't keep the car on track. In Drive To Survive you get to see Daddy throwing his weight around and essentially trying to run the team whilst Mazepin blames everything on the car (he had exactly the same car and chassis as his team mate).
The FIA asked Russians to sign a 'Neutrality and Peace' agreement at the start of the season. mazepin refused, as did another ex Russian F1 driver Danny Kyvat. From there his position in the team became pretty untenable so Haas let him, and the Russian money go.
Gene Haas who owns the team has now pumped more money into the team. Mazepin is stamping his feet on Insta basically saying how unfair it all is (not a comment on all the dead) and tbh I think his team mate will flourish without the added pressure of the Mazepin money.
Thats about it.