Percy is a visual testing and monitoring tool that focuses on detecting visual changes in web applications

WebLOAD – Performance and Load Testing for the Most Challenging Web Applications

Unifying API testing, API Performance testing, API Mocks and UI testing.

Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

Datadog is a cloud-based monitoring and analytics platform that provides observability and security for cloud-scale applications

Code, test, and deploy synthetic monitoring at scale.