Software engineers frequently struggle with understanding the relationships between the source code of a system and its requirements or high-level features. These relationships are commonly referred to as trace links. The creation and maintenance of trace links is a largely manual, time-consuming, and errorprone process. This paper presents STRADA (Scenario-based TRAce Detection and Analysis) ? a tool that helps software engineers explore traces links to source code through testing. While testing is predominantly done to ensure the correctness of a software system, STRADA demonstrates a vital secondary benefit: by executing source code during testing it can be linked to requirements and features, thus establishing traceability automatically.