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@LisaBabblebird Google evaluates not only who is referring to you, but also where you are referring to. Good sites share good links, bad sites share bad links. Yes, I would put links to client projects so you can link to them. Maybe nofollow if it's a small business

@JCN-SBWD Links from profiles practically do not count, and profiles are very poorly indexed. You can leave multiple links or one - it will be equally spammy. If you plan to maintain these profiles - another thing, put different links on different pages

@Gopal593 Why aren't you reading here? https://moz.com/learn/seo/domain-authority

No, DA can't go down because of outgoing links. It falls because competitors are getting more good links.