One solution is to partly outsource the development. You would try to build up a small team that deeply understands your business and the solution and and owns

One solution is to partly outsource the development. You would try to build up a small team that deeply understands your business and the solution and and owns the system can maintain it long term, but cooperate with a specialized service provider for the initial development (which will probably require more developers than you will want to ratain long term). Such a service provider will also be able to support you with he generation of the initial project vision, requirements engineering and usability/user experience engineering with experienced teams, whithout you having to hire for such roles out of the blue. While there are many such companies in Europe, I can recommend the one I just so happen to work for, mail me if you want to discuss it further.