Best ways to earn more ether

Hi, I have pretty big mining farm that has all ROI'd for over a year. I net about an eth a month at this point from mining. My question is what more can i do to earn more ethereum. I am a programmer (25+ yrs xp). I see NFTs as a possibility but what other options do I have to earn more eth? I have written some simple dapps but have never pushed anything to mainnet. With allthe advances in eth i plan to liquidate my rigs after 2.0 and just buy more eth. I dont know much about defi but am doing some research. thx