We all love to deliver well-tested and responsive software in rapid cycles to our customers. Consequently we invest a lot of time in test automation ranging from automated unit & integration tests to continuous performance testing. In this case study (Erste Bank’s George Online Banking) we follow the journey of introducing Gatling as simple tool to monitor the availability of REST endpoints. This monitoring turned out to be useful across multiple departments therefore a multi-tenant & multi-site test setup was introduced. To make the usage more convenient and accessible these tests were moved to a Jenkins automation server. Since Gatling test scripts are written in Scala you have all the programming power at your fingertips. The next step of the journey extended the Gatling scripts to compare the current JSON responses with recorded responses from the previous release in order to detect changes in the REST API. But at its heart Gatling is a performance test tool – turning the “functional” test suite into a full-blown performance test (including reporting) required just a few lines of code. At the end of this journey we look back at the separation of functional and performance test tools since both are means to the same end – delivering high-quality software.