Developers are businesses. So the socially motivated developer simply needs to be a business for people over profit. A social enterprise.
With a high level of transparency on the money going out of the business, to match the high level of scrutiny that we would subject such a company to.
Operating under a collaborative, human-centred design approach. Using principles that might look something like these.
Basically: Someone who works with us, and for us. Who values people. And cares about seeing good things happen to others.