Hi,
I am an european full-stack developer, expert in web development and criptocurrencies API implementation.
It is a big project, we'll have to discuss some technical points about it, but you were pretty clear.
I was pretty honest with you about my offer and the time i think it will cost, but we will do a great job, you will see.
It is ok to pay it at project completed, we are between professionals, but I know what you mean when you say that there are scammers all around.
Contact me by chat,
Thanks,
Roberto