Custom software is fully based on your unique business needs and goals. The software developer will make sure that they understood how your business runs and where would you like to take it. It is important that the professional knows the internal workflow as these are going to be very crucial in designing the software features.
Unless you are knowledgeable of the software development process, it is best that you entrust this project to the experts. It will take a lot of time and effort to understand the process alone and it would take a lot more to design and execute it. When you finally decide to customize your software needs, always go to a reliable provider.