This is actually something I keep thinking about too. From my perspective, it seems like a sensible thing to do for job security.
I can’t really help you find the kind of talent you need. However, if you are posting a buyers request looking for coders, this might be something you want to reconsider. Most veteran sellers don’t ever visit buyers requests.
Instead, you might want to break down what you need in your project. Is it a mobile app? Do you need someone who specializes in a specific coding language?
If you an do this, start using the search to find sellers by searching for specific search terms associated with what you need. If I was looking for a seller in pretty much any field, I would then look for someone with at least 200 majority 5-star reviews. Then message them with an outline of what you need and ask if they can help.
You might also want to use sites like GitHub to see if there are already any free and opensource software applications which you can use as the foundation for your own app or project. This can seem like a cheap and dirty way to do things. However, the software originally used in S K Y P E originated as code for an early 2000’s peer to peer file sharing platform called Kazaa.
If you can find an app or piece of software similar to what you need, you can then potentially save on costs by having someone modify it to your requirements. All you would need to do in this case, is make sure software has an opensource license.
Sadly, that is about the sum total of any practical advice I can give. Maybe, though, consider creating a new thread called something like “Calling All Coders.” - Not to ask for help with your project, but to advise you on how to find the best seller for what you need. It may be that it would get limited if any responses, as coding isn’t a big topic of discussion usually, however. it is always worth a try.