Tell them you did something unverifiable but technical.
"I started a game studio with a buddy from college. No, sorry, I don't have a TIN (tax identification number [IRS])"
Give them a number to a burner phone and fake an accent.
"Tom? Yeah we worked together at ___ I felt like he was a great guy to work with."
Tell them you were deathly sick.
"Yeah I had skin cancer. Nothing major but I had to take it easy and after beating it we all went on vacation to celebrate"
Tell them you lived the software engineer dream life
"After leaving my last job I wanted a change of pace so I went to become a bartender in Melbourne. It was all under the table"