It's definitely possible, but I agree with many other commenters it probably will not happen.
I wrote an encrypted mesh networking library that runs on normal operating systems. A customer asked me if I could make it run on an ESP32 with 520 kiB of RAM. At first this seemed impossible, but it turned out that it was, and not even that hard. While the original library was not memory hungry at all for a desktop CPU, it still wasted space on unnecessarily large buffers. Cutting those out made the library run on an ESP32 while leaving plenty of room for an application.
Also, my first PC was a 200 MHz single-core 32-bit AMD k6 with 32 MiB of RAM. This ran a graphical OS with browsers, word processors, 3D games and so on. Nowadays you can get a CPU with more than that amount of RAM as just built-in cache.
So a good place to start optimizing code would be to actually get a "severely resource constrained" computer and start making your code work on it.
I wrote an encrypted mesh networking library that runs on normal operating systems. A customer asked me if I could make it run on an ESP32 with 520 kiB of RAM. At first this seemed impossible, but it turned out that it was, and not even that hard. While the original library was not memory hungry at all for a desktop CPU, it still wasted space on unnecessarily large buffers. Cutting those out made the library run on an ESP32 while leaving plenty of room for an application.
Also, my first PC was a 200 MHz single-core 32-bit AMD k6 with 32 MiB of RAM. This ran a graphical OS with browsers, word processors, 3D games and so on. Nowadays you can get a CPU with more than that amount of RAM as just built-in cache.
So a good place to start optimizing code would be to actually get a "severely resource constrained" computer and start making your code work on it.