What to do if a competitor copies your design?

We have a small B2B application and have poured a lot of energy and resources into designing a great user experience. Our closest competitor just "overhauled" their own UX and it's a blatant rip off of our work.

Is there any recourse that you would suggest, if legal resources are limited?

If not a legal avenue, should we out them publicly and in addition to potentially get them to stop, get some publicity out of their ripoff?

Can you prove that they didn't poor even more energy and resources into their overhaul instead of copying your work? Did they use your graphics or icons? Did they copy your CSS? The answer is probably no, so any public accusations could hurt you and just starting that whole path is a waste of your energy as you should focus on customer development.

If you are sure they copied you and their design is very close to yours and you have screenshots of previous version of their site, you could write a blog post thanking them for flattering your work with before and after screens, comparing not only the visual design but also IA (architecture of navigation, text labels, error messages, any validation, etc).

Lastly, if their redesign came very close after yours (say within 2 weeks) and your products do the same thing consider the possibility of them coming up with it on their own. Copying someone's work without copying the front end code and design elements takes time - templates update, back-end tweaks to expose data points, and testing time at the very least.