Abstract: A system for testing candidate code to determine if the candidate code is approved for deployment to a production environment. The system may include a code testing engine configured to test a first code set of previously approved code to a testing server and a production environment including multiple production servers. At a deployment time, the code testing engine may then deploy candidate code to the testing server, while the production servers execute the first code set. Performance data for a time period before the deployment time and after the deployment time is collected. Latency data sets are fetched from the performance data sets and compared using multiple statistical tests. If the multiple statistical tests generate passing results, the candidate code is approved for deployment to the production environment.