Everybody makes mistakes, just because it is one of human characteristic. What is really important is to find them and to learn from them.
When you start building your home, you need responsible person, which is able to control construction works. He will provide weekly reports for you and provides you immediately information if they are important. Why are you doing? It is rhetorically question. But the software project is nothing else, is it simpler? No!
We can take control over whole process and represent your ideas, provide you support to select best offer, control partial results of work, make continues auditing of the work. Find out people for continuously testing, deployment and acceptance testing. It means you can get the best one.