When acquiring business software, AD&D pros still commonly frame their choices as build vs. buy, an outdated and inaccurate notion. Traditional build-vs.-buy thinking underestimates the complexity and cost of packaged solutions as well as the value of platforms and their ecosystems. And it overestimates the cost and complexity of modern custom development as well as the similarities between firms in a truly adaptive digital environment. In the digital era, software is an expression of the business. Firms can’t buy this; they must create it using a blend of customization and composition.