I'm a bit older than you but I only put the last ~12 years of experience on my resume. No need to date yourself. When I was ready to move on from my last job,

I'm a bit older than you but I only put the last ~12 years of experience on my resume. No need to date yourself. When I was ready to move on from my last job, I did a lot of mock interviews, both on pramp.com initially for free, then later interviewing.io for paid interviews. That helped a lot. You should not have a "five year gap". Presumably you started a company, did you register the company? Put your failed company name, and put yourself as CTO or Chief Engineer or something.