They chose Gatling
"Gatling helps KLM to move from a project oriented to a continuous delivery organization by enabling the integration of load and performance testing into the continuous delivery process.
Being a developer friendly tool, that integrates well with other development tools used at KLM, Gatling was quickly adopted by developers in the product teams.
By integrating performance tests in the delivery pipeline, the teams get daily feedback on performance during a sprint, so that they can detect and solve issues early in the development process."
"Gatling has very quickly replaced legacy load testing tools by providing great flexibility, efficiency and integration to our existing processes and test environments.
Removing some of the bottle-necks of API load testing allowed us to achieve more comprehensive and relevant results.
Combining those benefits and improved acceptance of load testing within development teams, led to a significant increase in software quality and customer satisfaction.
At the same time, we experienced a ~150x enhancement in efficiency regarding test execution, bringing down our investments on load testing dramatically."