I have a few "ripples" in my exterior too. I know where each one is and they are a normal thing as far as I am concerned. In fact, changes in temperature and humidity make them better / worse. I keep an eye on them just to make sure they don't develop into anything. They seem to be where a major support, i.e. aluminum, is sandwiched in the wall.
As posted, a few picks would help us say if they look like they might be an issue.
David