I just created a cryptocurrency called denaro. I used Python and PostgreSQL. It's a fully working crypto written by 0, it does not operate on any external blockchain like ethereum, it does have his blockchain. It started like "let's see if i can really make it", and it ended that i did it. It can theoretically confirm up to 5 transactions per second, with a maximum block size of 2mb. You can find it on github: https://github.com/denaro-coin/denaro. If you wanna contribute, you're welcome. I also created a telegram bot wallet (@DenaroCoinBot), so feel free to pm me on @gaetano555 and i'll send you some.