Website/UX Designer with development skills

I’m looking for a designer with front-end development skills in HTML and CSS.

In the past I’ve worked with designers, but ran into two problems:
1. They were making wide-ranging changes to the website that are difficult to break down and implement consistently
2. They were optimizing for a happy case, but often we need to deal with unwieldy data or the limitations of our charting library

So I’m looking for someone who will make concrete CSS/HTML changes to our website code that are easy to implement. (That’s the focus, always open to hearing about more advanced suggestions as well.)