Software developers have many information needs which could be answered using the various repositories at their disposal, but they underutilize these knowledge resources for a variety of good reasons. Backstory is a search tool for software developers aimed at addressing those reasons, and so to improve knowledge flow among teammates. This paper presents as background the results of a survey of developers’ current search habits and desires for a new tool. A case study of root-cause analysis is also presented, which informs the design of Backstory and adds detail to an accepted model of sensemaking. The Backstory UI is described with respect to the needs identified in the survey and user study. Finally, the Backstory UI design suggests that a tool can support sensemaking in such a way that it’s not intimidating or distracting for simple investigations, yet has mechanisms that the user may employ incrementally as the complexity of an investigation increases – a characteristic referred to here as scalable sensemaking .