At my workplace we're using a modified version of ShadowReader - https://github.com/edmunds/shadowreader; https://github.com/edmunds/shadowreader; note it is

At my workplace we're using a modified version of ShadowReader - https://github.com/edmunds/shadowreader; https://github.com/edmunds/shadowreader; note it is AWS-specific. It works by re-running the load balancer logs, either in near-real time or a replay window. We use it test changes to our Solr search engine. It complements our Locust testing which is more about red-lining our servers and isn't as user-specific.