CSSEazyMockMockAPIGuidearchitecturehex-archgosystem-designNextFeatureBlogsAIMasteringFPMonadsFunctionalFEanimationGoProgrammingTanstackReactprinciplespatternsProgramingRecursionFunctionalTestSmokeTestUnitTestSystemTestSanityTestAPITEQNOLOGICALEAZYMOCK