It's not particularly magical, there's consumer chips around which are not a whole lot bigger (though obviously in a more standard package). You don't get a lot of resources, but you don't really need it if all the other frameworks are in place in other software. If this sort of thing is something you can buy on Mouser for a few cents, the espionage grade material is probably an order or magnitude more higher quality.

https://www.microchip.com/wwwproducts/en/ATtiny4

For scale, this alone is about the size of a large SMD capacitor and would basically be lost in most designs today.