I have been using LaTeX for a little over two years now. I mostly use it to prepare homework solutions in mathematics and engineering coursework. I also use it to document my research and writing some reports.
Recently I have started to use it for my resume, because I find the formatting to be significantly more stable than anything I can get using Microsoft Word. However, I have not been able to find a satisfactory resume class, so I am now modifying a resume class to suit my needs.
To improve the resume class, I am now trying to make some new environments and commands to make the construction more intuitive. The class file that I am modifying appears to be in Plain TeX, which inspires my question.
Are there certain layout and design problems that can only be solved using Plain TeX, or can everything be done using LaTeX?