Before we jump into the programming itself, let us learn some of the so-called weak points that you might be able to consider and improve on ( or even share) with others out there to make the platform a better one.
First is speed, the information that I might have come upon may be a bit outdated but it still shows a significant disadvantage when it comes to speed of processing as compared to other more stable platforms. The use of green threads is also subject to criticism by many making it very difficult or unstable in certain user-case scenarios. Unicode or multi-byte string support is not yet native and the use of global variables is the biggest pitfall so far known. This trait unfortunately allows global variables to be modified from anywhere and we mean anywhere. Ruby also lacks a well-defined specification with it being referred to as an implementation of C. Most of these issues have been thought of and are to be addressed in the coming release of the newest versions of the programming language.