T7 is the name of the Deutsche Börse’s trading system used for the XETRA and EUREX exchanges delivering ultra-low latency, robustness, and safe handling of very high throughput. It is considered a critical component of the worldwide financial service infrastructure. Each new release undergoes extensive testing to ensure the reliability and integrity of the system and thus the stability of the global financial markets. Utilizing the flexible capacity of cloud services for development and test enabled Deutsche Börse to break through the limitations of an existing on-premises server farm. T7’s various test types like regression test, smoke test, and chaos monkey as well as mass compiles benefited differently from the cloud usage. Still all services come at a cost and finding the optimal balance between sufficient testing time, capacity, and budget is a challenge. Learn how the T7 team could drastically reduce the cost with EC2 Spot instances and increase test coverage with AWS Transit Gateway multicast.