Most organizations that don't have the resources to custom-build their software will select out-of-the-box or SaaS solutions to meet their requirements. All too often, however, these solutions tend to aggressively expand their scope to entangle themselves into every part of your business. This blurs integration boundaries and makes change less predictable and slow. To mitigate this risk, we recommend that organizations develop a clear target capability model and then employ a strategy we call Bounded Buy—that is, only select vendor products that are modular and decoupled and can be contained within the Bounded Context of a single business capability. This modularity and independent deliverability should be included in the acceptance criteria for a vendor selection process.