A premise for the efficiency of software developers is clarity on understanding the requirements, as well as the business people maintain the same mutual alignment. Behavior-driven Development (BDD) proposes based on a specific scenario, perceives a problem and correctly directs a solution. This case study shows how BDD helps three agile teams from a Financial Institution to deliver a complex credit platform solution, which at first had critical flaws to bring the product, and how they overcame it. In scenarios where a more focused understanding of a problem is required, it was observed that BDD brought a positive influence for the performance of these teams. While maintaining mature ways of working by improving communication, a mutual understanding of the product added a direction regarding priorities, bringing fast flow with quality. Given the good results, this institution intends to extend the use of this technique to other teams that support critical issues.