Ask HN: is it ok to list past achievements as employee in consultancy portfolio?

I have a CS degree and a few years of employment as a web/software developer. The next step is starting a software consultancy, as a sole founder.

The problem: the main items on my portfolio would be my achievements as an employee of the companies I've worked for. Can this be a problem? Since these items are not done by “my company for my clients” but instead by “me, the person, as an employee”.

Hope my concern is somewhat understandable.