20+ years wearing many hats. Currently senior software engineer. They wisey stopped letting me touch code and forced me to manage an organization
I think a certification in AWS or Azure would be valuable if he were looking at software engineering. If he were going down the developer path, I think going to a highly regarded boot camp could be a faster path to employment IF he has a genuine interest. If he really loves it, then building a portfolio to show your skills will be a pleasure.....which brings me to....
Build a portfolio of your work. We ask every applicant if we can see their public bitbucket repo (this is a site where you can share code with others).
On the networking side, I don't know how certifications are regarded today. My salary doubled when I got my MCSE 4.0 back when dinosaurs roamed the earth. The Cisco certifications helped as well.
For a career changer, I think certifications can be a viable path to getting you foot in the door. If you took the initiative to get the certification, and can back in up with genuine interest and appropriate knowledge, I think that's a compelling narrative.