While developing customsolvers.com, I tried to maximise the following aspects:
Usability. I also tried to make customsolvers.com as intuitive and easy-to-use as possible, but without affecting its efficiency and reliability. Additionally, it is also optimised for a wide variety of screen resolutions and versions of all the major browsers.
Modularity. Writing highly modular and scalable code was also one of my main concerns while developing this site. In fact, most of its database reliance is precisely meant for improving the code modularity/scalability; an approach which is certainly not the most efficient alternative.