Because of all the rhetorical noise that can come with a hugely complex industry such as software development, you can accidentally lose sight of this fundamental question. The fact is, the only thing that matters to your client is “does this program do what I need to do, and does it do it reliably?” The way to ensure this is a simple, yet elegant development solution: unit testing.
When developing a new software feature, you might take the naive approach and hand your engineers a rough specification, and have them implement your ideas to the best of their ability. Then, although they might have even designed a good feature, sometimes it just isn’t what you or your client needed. The perfect solution to this is test-driven development and unit testing. Using this method, instead of making guesswork of what needs to be done and then testing it later, only to find that the feature isn’t quite right, you instead write the tests first, ensure that they fit exactly what you want your piece of software to do and only then begin development. Initially, all the tests will fail. But as your engineers code the feature, they code specifically to pass each test, and as a result they code exactly what you need to get your feature working, released, and useful.
Unit testing is especially important in incrementally released software. As you continuously roll out scores and scores of new features, it can become impossible to make sure the entirety of your program is functional. On a piece of software that is even two years old, there can be hundreds and hundreds of features that need to be ensured to work. It cannot be assumed that if a feature worked in a previous release that it will always work, as software engineering is an inherently finicky task, and the most minute change can break features for reasons entirely unknown. This is true especially if you have to change the fundamental structure of the program in order to roll in the new feature, which happens more often than you might think.
In addition, manual testing requires your engineers to repeatedly execute repetitive tasks. Saving your engineers’ time, especially by running overnight test suites, can in addition save your company a good amount of money.
There are scores of software development services created with automated unit testing and test driven development in mind. There’s one in any competitive IDE and one for virtually any language. Without a doubt, there’s multiple automated testing software development services for whatever technology you decide to develop your product with. Automated unit testing is a simple, elegant way to ensure a viable, reliable product, it reduces development costs, wasted time, guesswork, and headache for everyone involved, and all of the tools and services are already in place for you to integrate it seamlessly in your enterprise. In light of this, automated unit testing is, without a doubt, an indispensable practice to any software company.