A command line or terminal developer primarily interacts with a computer system using text-based commands, instead of graphical interfaces. They write, debug, and execute scripts, automate tasks, manage files, and administer systems. They use various command-line tools and languages, like Bash, Python, or Ruby, and work with APIs, databases, and servers. They are also responsible for version control systems and often work with cloud-based platforms. Their role involves troubleshooting, optimizing system processes, and ensuring system security. They need strong problem-solving skills, attention to detail, and an understanding of operating systems and networking.