The Testing Pyramid is a useful model that can help organizations approach microservices testing. The model was originally developed by Mike Cohn in the era of service-oriented architecture (SOA), a predecessor of microservices architecture.
The basic idea is that to thoroughly test a system, the largest number of tests should be automated unit tests; there should be a smaller number of service-level tests testing interaction between components; and the smallest number of tests should be end-to-end UI or system tests.