I guess you can search for developers on GitHub. Look for professionals in the specific field. But don't spam people that have job. Find few great developers an

I guess you can search for developers on GitHub. Look for professionals in the specific field. But don't spam people that have job. Find few great developers and send them personal email. Also there are marketplaces that claim to have top developers. E.x. grouptalent.com, toptal.com etc. But I never used them. Also search for similar question on Quora. It has lots of great answers.