Blackfire.io - Blackfire empowers all PHP developers and IT/Ops to continuously verify and improve their app’s performance, throughout its lifecycle, by getting the right information at the right moment.
Apache JMeter - Apache JMeter™.
NewRelic - New Relic is a Software Analytics company that makes sense of billions of metrics across millions of apps. We help the people who build modern software understand the stories their data is trying to tell them.
GTmetrix - GTmetrix is a free tool that analyzes your page's speed performance. Using PageSpeed and YSlow, GTmetrix generates scores for your pages and offers actionable recommendations on how to fix them.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Loader - Load testing and tracking application