The topmost priority before the release of any software product is providing quality assurance that satisfies user expectations and demands. To ensure that the application performs seamlessly, functionality across web pages, forms, database connection, call-to-action forms are checked using functionality testing.

Sanity testing is considered as a subset of regression testing where all the modules are combined at the prior of release and the functionality of the application is validated. The sanity testing also validates whether there are any impacts in any of the modules and also ensures that all the modules are working as expected.

Regression testing is a functional testing strategy that validates all the existing software applications to make sure any change or addition has caused an impact on the existing functionality. By employing regression testing, maximum test coverage with a minimal number of test cases is achieved. By re-running testing scenarios and selecting relevant test cases from the test suite that covers both modified and affected parts of the code.

API testing strategy conducts tests on the API layer to validate that all the integrated applications with the system act the way they are designed. API testing also validates the flow of data and information between a few different API connections. Quality engineers adapt this testing strategy to ensure that the Developed API meets expectations in terms of reliability, performance, security, and functionality by detecting bugs and inconsistencies in the application.