Knock provides a flexible notifications infrastructure that allows developers to manage notifications across various channels without the need for custom application code. The decision of whether to build an in-house notification system or use third-party solutions is explored, emphasizing the challenges and complexities of managing cross-channel notifications as products scale. Key considerations in this build vs. buy analysis include total cost of ownership, the need for specialized expertise, maintaining visibility for non-technical teams, consistency in user experience, and compliance requirements. Enterprise-scale notification systems often feature intuitive dashboards, role-based access controls, comprehensive audit logs, real-time delivery infrastructure, and observability tools, which can be more efficiently managed with third-party solutions rather than building internally. Knock offers out-of-the-box solutions such as APIs, dashboards, and composable components that streamline the process of integrating notifications into products, making it an appealing option for teams looking to avoid the complexities of in-house development.