The goal of your answer is to communicate your working knowledge of photography software applications. If you work in software other than the industry standard Adobe apps, include that in your answer.

Avoid rating yourself a 10 unless you are an expert on a particular application and can speak to that expertise. Rating yourself at 10 on multiple apps can come across as cocky. It is also unlikely that someone will be a 10 on multiple applications.

I work in Photoshop and Lightroom on a daily basis. I would rate myself as an 8 in Photoshop and a 9 in Lightroom. I wouldn't rate myself a 10 in either of them because there is always more to learn. I use Photoshop for deep edits or when I need total control over an image for a complex composite. Lightroom is a powerful tool in its own right, but it is not as in-depth as Photoshop. I think Lightroom's tool interface is easier and faster, and I use it when I need to make image adjustments on projects with a tighter turn-around.