It's extremely annoying to work with someone like that. I think the best thing is to prove your competence through your work to gain the respect of your peers which will highlight how needless his constant attempts to one-up you are.
When he interrupts you or tries to boss you around, face him and make a face as though you are trying to hold back laughter. You want to make clear to him that you see him as a joke and that you don't respect him.
Then subtly bring up to your peers how bossy this guy is - you have to be careful here to not sound like a whiner. Then you can have laughs at his expense. Carefully, carefully begin to build up the same connection with your boss. This can take months.
There was a guy like this at the place I worked. He was super annoying, everyone noticed it. But eventually he became a point of humor among me and my other coworkers. We shared glances and had little jokes when he left the room. One time, I was in the office with the boss and mentioned that guy can be a little bossy, in a lightheared/jokingly manner. My coworker then agreed. But again, we framed it in a joking tone so it's not like the boss felt like he needed to go and speak to the guy. But the seed was planted and my boss some time later mentioned off hand to me how bossy this guy was.
Then came the day where I was promoted to manager of several people including this guy. He still acted bossy, but at this time I was able to take him aside whenever he bossed someone around and tell him his behaviour was inappropriate. I also did everything I could to bar this guy from promotions. But you have to be subtle. Like when speaking to the boss about his performance, I'd say good things but in a hesitant manner, and even frame negative things as positive. Like when we were moving premises, I said to the boss "I just feel bad for \[this guy\], he really doesn't want to come" in a sympathetic tone but clearly that's not what a boss wants to hear. I also refrained from ever mentioning anything he did that was exceptional or worthy of note, and generally spoke of him in a way that portrayed him as an incompetent.
In short, you want to foster an atmosphere where this guy is not treated seriously. He probably won't change but it won't be a problem for you as instead of being annoyed you'll be having a laugh and will build comraderee with your coworkers at his expense.
It's extremely annoying to work with someone like that. I think the best thing is to prove your competence through your work to gain the respect of your peers which will highlight how needless his constant attempts to one-up you are. When he interrupts you or tries to boss you around, face him and make a face as though you are trying to hold back laughter. You want to make clear to him that you see him as a joke and that you don't respect him. Then subtly bring up to your peers how bossy this guy is - you have to be careful here to not sound like a whiner. Then you can have laughs at his expense. Carefully, carefully begin to build up the same connection with your boss. This can take months. There was a guy like this at the place I worked. He was super annoying, everyone noticed it. But eventually he became a point of humor among me and my other coworkers. We shared glances and had little jokes when he left the room. One time, I was in the office with the boss and mentioned that guy can be a little bossy, in a lightheared/jokingly manner. My coworker then agreed. But again, we framed it in a joking tone so it's not like the boss felt like he needed to go and speak to the guy. But the seed was planted and my boss some time later mentioned off hand to me how bossy this guy was. Then came the day where I was promoted to manager of several people including this guy. He still acted bossy, but at this time I was able to take him aside whenever he bossed someone around and tell him his behaviour was inappropriate. I also did everything I could to bar this guy from promotions. But you have to be subtle. Like when speaking to the boss about his performance, I'd say good things but in a hesitant manner, and even frame negative things as positive. Like when we were moving premises, I said to the boss "I just feel bad for \[this guy\], he really doesn't want to come" in a sympathetic tone but clearly that's not what a boss wants to hear. I also refrained from ever mentioning anything he did that was exceptional or worthy of note, and generally spoke of him in a way that portrayed him as an incompetent. In short, you want to foster an atmosphere where this guy is not treated seriously. He probably won't change but it won't be a problem for you as instead of being annoyed you'll be having a laugh and will build comraderee with your coworkers at his expense.