I had a buddy who started flying as a kid, got with an airline as an aircraft mechanic that gave a big discount on rentals, by the time he was in his mid 20's he was working as a flight mechanic for a 742F operator. They soon gave him a slot as an FE, he went in on a twin and built multi time at the same time building hrs on the 742 and getting paid. It was not long before he had his ATP minimums and first commercial flight was a 742.