As a one man army indie game developer I basically can no longer maintain my code-base without going crazy because it's grown to the point where it's no longer

As a one man army indie game developer I basically can no longer maintain my code-base without going crazy because it's grown to the point where it's no longer a one man job. I knew this would be a problem, so keeping code complexity to a minimum has always been a priority, but it's no longer possible to keep up. Thankfully it's reached maturity as a product and is a fun and profitable game. Many people think i'm 'brilliant' when they see the product and they hear i'm the only the developer and it's a custom 3d engine. But truth of the matter is much of my brilliance was stubbornness and cleverness in keeping things simple and code complexity to a minimum. The problem is you run out of memory in your brain. You forget how systems work. You have to trace back through the code and "reload things". When you have to make a modification. When I hit my human ram capacity so to speak, i was extremely frustrated that I couldn't make the boundlessly quick progress that I used to. But then you get used to it, and just accept that it will take time when you switch from one subsystem to the other, to load up the relevant parts of the code into your human ram in order to do be able to do the work you want to do. The simpler and more straightforward the program architecture, the easier it is to jump into and out of and write new code. Of course understanding what your product is and is going to be helps tremendously in making sure you can design your program in a sensible way.... I've been lucky enough to have a firm intuitive understanding of future the design of the game and it's features as it was being formed. (not being at the mercy of clients or bad managers is a wonderful thing) What i've noticed is a big difference from me and friends with small development studios that accomplish less with a lot more sweat. Is that I don't develop fully featured flexible systems when simple ones will do, I don't roll my own code when good/simple libraries or apis exist. I'm trying to make my product a work of art, and the code is functional and simple. Where often I see other good engineers try to make their code the work of art. Which leads to lots unnecessary code complexity because they engineer systems designed to be future proof for everything, instead of of what realistically will be necessary for the future of the project or projects. A system with 30 components is easier to understand and easier to maintain than a system with 100. More functions, more objects, and more abstractions. Often mean more components and code complexity. Which ultimately means it's going to take more brainpower to get anything done. Which is why it takes teams of 100s to maintain large enterprise software projects where the incremental updates change very little even though the engineers working on it are educated well trained people. shrug