Where do we find a good developer or company to build with OSM?
OSM is a global, open community. There are many organizations and companies that use OSM and there are also developers who build tools and processes using OSM. The OSM Foundation is does not vet developers nor maintain a list of developers.
We recommend that you join the community, investigate some of the networks and groups involved, and ask questions. There is a lengthy list of commercial services for OSM on our wiki. Depending where you are in the world, there are local OSM chapters, local country-level mailing lists, as well as local events. Hiring a developer with any niche skills, such as expertise in OSM and the related technological applications is the responsibility of each business.
The Get in Touch page has suggestions for how to reach out and talk with the community.