It is a joy to build command-line tools that are not only easy to learn, but that other developers are willing to maintain. Often a team's engineering efforts are spent on the backend, while the cli doesn't receive the same level of attention. This can result in hard-to-test tools, and dumping maintenance of them to whoever most recently joined the team. Learn how to take full advantage of popular Go libraries, structure your Go code to improve reuse and testability, publish binaries, and of course design your commands to be user friendly.