Even though Lean principles have already been broadly applied to the manufacturing industry , we cannot say the same regarding software development. The objective of this article is therefore to present a real experience where the Lean Kanban method  was applied by a software development team from an IT consulting firm. The team (7 people) is responsible for the maintenance of internal management applications at a large governmental organization (over 4,000 employees). It had to combine new evolutionary developments with corrective maintenance and incident resolution within the production area of 20 to 25 information systems with heterogeneous purposes and technologies. After some time, this kind of IT teams (very common in the public administration) that deal mainly with legacy applications use to work in an isolated way: they do not belong completely either to the IT consulting firm or to the public organization acting as contractor. This context uses to hamper the agile culture of continuous improvement and need from additional efforts to keep the team focused and motivated. Different indicators were defined, some of them were directly related with standard Lean metrics, such lead and cycle time or pro- cess throughput . Likewise, given the nature of the team duties, the number of petitions waiting to be attended in the buffer was also considered. By the end of the project, a significant improvement was observed in these four indicators. We believe that the contribution of this paper lies therefore on the lessons learned from the experience of applying and adapting the method.