You're right, my thought experienced only proved that it is possible for a developper to be 10x better than another one, with the same brain, only more experien

You're right, my thought experienced only proved that it is possible for a developper to be 10x better than another one, with the same brain, only more experience. About your project, i had the experience of building the exact same project ( an product demo ios app with a web backend and its content management interface). First project had to be done using "enterprise" practices, and the other was free. First one i did with a senior developer helping me on the web interface side, the other with an intern i had to explain what MVC was. First project took 6 months, plus 2 more because of some guidelines i didn't respect first, plus a whole team of admins to handle the production side. It probably costed more than 100k to the company ( not counting the internal days spent in meetings). The internal team that was supposed to maintain the code wasn't able to do so. The other took less than 3 months and costed something like 10k, including server cost (i used app engine). The intern made the project evolve for more than a year. A 10x developper is not just able to produce more, it can prevent you from falling into traps that can simply lead your product to a complete failure, and your company to simply cease to exist.