In this chapter, we presented the development life cycle that follows the test-driven strategy. We went through the process of defining acceptance tests, and we implemented and executed integration and unit tests. Then we presented, ideas on using black box testing to increase our data coverage.

By testing every layer of the application, the number of bugs is reduced, maintainability enhances, and productivity increases. Scalding offers remarkable testing capabilities, satisfying all the requirements to build robust and complex MapReduce applications.

In the following chapter, we will discuss how to run our jobs on a production cluster and how to configure, monitor, and optimize them.