There are two speedrunners on top of the world right now. It's literally the Hitman 3 level "On Top of the World". It is the first level of the game and was completed by Any% speedrunners in a truly shocking 9 seconds. Himitsu" Run forward and shoot the gun.

Speedrunner Wreak completed it in 9 seconds on January 22, followed by Der_Lauch_Linus on January 23. This speedy completion was due to the funky structure of this level. The Dubai level takes place on the top floor of a skyscraper, and at the moment after the level starts, both targets are visible on the balcony above Agent 47's starting point. So move fast, aim well, and shoot them both down in seconds; Wreak's record can be found here and Der_Lauch_Linus' record can be found here. Bonus points to Wreak for wearing a dumber costume than Linus. These are Any% runs. In other words, just follow the Speedrun.com rules to complete the goals.

Not sure if you can do it in 8 seconds; the few milliseconds that Wreak and Linus have their shots poised are crucial. Someone must have already tried. On the other hand, Silent Assassin's record is only 7 seconds.