>>29
I'm thinking smart contracts in some sort of proof of stake gambit. You can add and remove things until both parties sign and agree. Additional contracts could be made for arbitration and third party neutrality, but again all 5 need to sign.
For developers that just want to code, their code would be encrypted until the bid reaches the time limit or threshold, and the decrypt key laid bare.
The current offerings aren't appetizing:
https://bdu.dev/
https://gitpay.me/
https://www.rysolv.com/
https://opencollective.com/