Personally it feels like every issue gets shoved under the "imposter syndrome" umbrella, but I'd say you are just feeling a bit of cultural shock or cultural mismatch.
The other thing is software developed by large teams tend to be complex, and a new-comer needs more time to understand what's happening. Onboarding can be a very chaotic process especially for teams who don't specifically put a lot of effort into making it smooth for new-comers. This isn't imposter syndrome but rather something that your team probably needs to do better.
The complexity you are probably going to have to get used to. Maybe some of it is unnecessary, but just like the naïve developer trying to refactor/rewrite a complex piece of code realizes, the extra exceptions and special cases were added for some reason and without them the code breaks in various niche situations. (Or maybe they're really unnecessary! The thing is until you get a full grasp of the code, you won't know)
Otherwise just give it a couple months and see how well you adjust. I think just keep an open mind and don't assume things only because other people have different backgrounds from yours. (I mean, what does age have to do with this? You're only a couple years older than those "fresh 20 year old kids", not even "old"...)
The other thing is software developed by large teams tend to be complex, and a new-comer needs more time to understand what's happening. Onboarding can be a very chaotic process especially for teams who don't specifically put a lot of effort into making it smooth for new-comers. This isn't imposter syndrome but rather something that your team probably needs to do better.
The complexity you are probably going to have to get used to. Maybe some of it is unnecessary, but just like the naïve developer trying to refactor/rewrite a complex piece of code realizes, the extra exceptions and special cases were added for some reason and without them the code breaks in various niche situations. (Or maybe they're really unnecessary! The thing is until you get a full grasp of the code, you won't know)
Otherwise just give it a couple months and see how well you adjust. I think just keep an open mind and don't assume things only because other people have different backgrounds from yours. (I mean, what does age have to do with this? You're only a couple years older than those "fresh 20 year old kids", not even "old"...)