I have the exact same feeling though I have only 6 years of experience(being 29 years old). At this point ~90% of the code we have, was written, touched or refactored by me, so I know everything in my org, I know services we use, even 3rd party ones, I do my work usually twice as fast as other developers, my contributions double the amount of the developer behind me. I am the guy that everyone comes to with problems, issues, ideas, architecture questions. I had similar experience in all previous companies.
At the same time, I feel the impostor syndrome hitting me hard, I never worked at big tech, never worked on multi-million-user applications. I know there's a lot that I don't know or things that I have never done. Yet, whenever I look at tech 'influencers', people who give talks, write articles, I feel like I'm nothing compared to them, like I don't know anything. That's why I'm switching jobs now again, to see new stuff and meet new people, see what's out there. This way I have somewhat of a challenge for at least the first year of new work, new environment, new project.
At the same time, I feel the impostor syndrome hitting me hard, I never worked at big tech, never worked on multi-million-user applications. I know there's a lot that I don't know or things that I have never done. Yet, whenever I look at tech 'influencers', people who give talks, write articles, I feel like I'm nothing compared to them, like I don't know anything. That's why I'm switching jobs now again, to see new stuff and meet new people, see what's out there. This way I have somewhat of a challenge for at least the first year of new work, new environment, new project.