Which short course helped you get hired? after 18 years as a graphic designer

I am considering a short certificate to improve my chances as a graphic designer. I worked as a graphic designer before this. I can study evenings. Which ones are overrated?

Thanks for writing this out. I went through something close to it 14 months ago, and it settled down once I kept a simple log of every call and form.

A hands-on course with a project helped more than a purely online one.