Coyote helps solve the complexity of developing asynchronous software. It helps you with design and implementation by providing optional high-level programming abstractions. It helps with testing by providing support for writing detailed system specifications and a very effective high-coverage testing tool. The integration of these features into the same product helps you iterate faster through the design-implement-test-revise cycle of software development.
Coyote allows you to develop with confidence! That confidence comes from having your code changes be backed by powerful automated testing. This has allowed teams to move at a faster pace, often finishing features in a fraction of the time compared to developing with legacy techniques where the uncertainty of vetting corner-cases (especially with concurrency, failures, etc.) weighs you down heavily. The confidence also results in better performant code because Coyote helps you validate even highly-concurrent designs.
Testing with Coyote is designed to be easy and effective. It removes the mystery associated with finding concurrency bugs and the pain associated with debugging them. Any bugs reported by the tester can be replayed: something that does not come for free otherwise for programs with concurrency. Coyote testing can be integrated with standard unit-testing frameworks, or easily parallelized for boosting coverage. It also makes it easy to visualize the coverage obtained for a test.
Coyote is designed to be lightweight, adding no runtime overhead through binary rewriting for testing unmodified task-based programs. You can also choose to build your application logic using the more advanced asynchronous actor programming model of Coyote, which is high-performant and used by several teams inside Azure. It is easy to get started: simple design will have simple implementations, and a smooth on-ramp from simple to advanced usage of Coyote where the return on your investment depends on how much of Coyote you use in your system.
Coyote has been battle-tested by Azure. There are several Azure services written using Coyote that are currently running live in production. We build on the experience of various teams that cover a wide spectrum of requirements.