Multiple applications with shared libraries on v3.x

Hi,

I am not new to CI development but it's been some 5 years since I last worked with it.

While developing a website I though about using the same libraries (system) in 2 applications, the frontend and admin of the website, and was wondering what would be the best approach to do so, if I just need to rename the paths in the index or something else I should be wary of.

Thanks in advance.