I'm a manager at a medium-to-large corporation in Arizona. Some details have been anonymized, including the state.
We recently hired a Junior Software Engineer with about 1 year of experience several months ago who is baffling our management and other developers. In most cases, he is able to vastly outperform Senior and Principal Software Engineers without even trying.
He came here despite not knowing our technology stack, and learned to use it better than many of our current employees within a month. To make matters more interesting, he is repeatedly discovering, documenting, and fixing security holes that would've cost our business a tremendous amount of money if exploited.
We've tried to give him very difficult tasks, and even one we've deemed impossible, and he's completing them very quickly. We assign hundreds of hours for him to complete a programming task, but he's completing them as fast as 1 hour on some occasions. The hardest one, when he was still learning our technology stack, took him only two weeks; we were expecting it to take anywhere from 3 to 4 months.
His projects are finished perfectly. He's the only one merging code that actually works correctly the first time, unless there's a problem on our end. He does exactly what he's told.
Unfortunately for him, management feels the need to capitalize on his impostor syndrome so they won't have to give him a raise. He's starting to realize his value, but management is not having it.
We've even gone as far as having him work on four different teams, but he's finishing his assigned work before everyone else. The result is that he sits around doing nearly nothing all day because there is nothing for him to do. He keeps asking for projects, and we continually try to challenge him, but he's completed more than a dozen projects in just 8 months. Our average yearly workload is about 4 or 5 projects.
To make matters worse, he was recently caught watching videos on YouTube, and was written up for it. He's one of the lowest paid developers on our team, and unfortunately, upper management doesn't want to pay him more, or give him a higher, more important position.
How can I convince management to stop taking advantage of him, and let him do his own thing when there's nothing to do?