Unit testing is an indispensable practice for Java developers (any developer really). The primary benefit of unit testing a pipeline is the early detection of bugs, which is less expensive to fix. It not only improves the overall quality of the code but also makes future maintenance easy.

Using lambdas specifically with streams in Java makes code concise and readable. Streams are excellent for filtering, mapping, sorting, and reducing operations. The elements in the sequence are better processed in a declarative and functional manner, something which lambdas exactly fit into. The anonymous functions that are written with lambdas not only facilitate a functional style of programming but also enhance the expressiveness of the code. Streams and lambdas were introduced in Java after JDK 8, and since then, Java developers have used these features frequently in their projects.