Dev goes to work for his first large company, sees his first large legacy codebase, says "wat?! Yuck!!"

Also, he explains he was the savior of the entire enterprise and did everything and is super amazing but other people kept having different opinions and his boss didn't like his idea for a project that would take 5 years to achieve the immediately needed change, so he left the large company.

Bonus: It only took him 5 years to decide he didn't want to be at a big company with a legacy codebase.