Testing of modern N-tiered applications needs to follow the test pyramid model of test priority, which is unit tests forming the basis of testing, followed by API testing, followed by integration testing (which includes UI testing). API tests are faster to develop, maintain, and execute than more complex integration tests, therefore, they can find bugs more “upstream” (earlier in development cycles) than integration tests can, forming a middle ground between unit tests done by developers or SDET’s and integration tests done by various testing stakeholders and business analysts.