I've got 20 years of experience and have never bothered with side projects, portfolios or the like. You have to have the confidence to pitch your real experience and let it shine on your CV and at interview, both from a technical and people point of view. That's what hiring managers are looking for from someone who has been in the business for a while.

If you get rejected because you don't have a recent GitHub project, that's their loss, and they don't know what they're missing.