If you intend to build a large scale custom web or mobile application, you should invest your time to plan your project in detail before any development starts. Like building a house, a home owner does not go directly to a building company and have them start laying the foundation without any planning. He will first enlist the services of an architect to plan and blueprint the house. The same is true for custom application development where a Solution Architect can help you research, design, plan, estimate and document your project in detail before any developers start working on it.