An understanding of Non-functional Requirements (NFRs) is important for designing a software system, however, time and resource constraints, usually, lead to systems being developed mostly from a functional perspective. We explore the case of using programming libraries as a support to the design of software systems explicitly considering NFRs. We tackle the case of the React JS library, within the context of reengineering a Web based e-commerce software. This library operationalizes a set of NFRs needed for a system to be reactive. We abstracted these implementations as softgoals to derive an i∗ model with the NFRs made explicit. The resulting model, created collaboratively, is an example of using both functional and qualitative perspectives in designing a software system.