Maybe I am weird but I like doing stuff like that. I am more of an optimizer than from-scratch-creator so I like having a starting point. Then you just refactor your way through the system while adding new stuff and fixing bugs. I also like debugging and profiling :-(.
Here! I spent a lot of my early career porting legacy code from one language/platform to another and I liked that well enough. Now I spend more time refining my own code than is really necessary, just because I enjoy it.