If you've never done it before, I highly recommend writing a single program with multiple front ends: GUI, TUI, CLI, API. Wrap them up in multiple interfaces: f

If you've never done it before, I highly recommend writing a single program with multiple front ends: GUI, TUI, CLI, API. Wrap them up in multiple interfaces: for GUI, make a web-version, a desktop version, a tablet version, a smartphone version, etc. And do it in as many toolkits as possible. At first, you'll want to keep the program simple. My first time doing it, I made a super simple "simulation" of a fish tank. The fish just moved at random. They'd sure if you didn't feed them regularly. That's about it. It's a highly beneficial learning experience. You get the case functionality done, and then you start implementing new features. And you start to see all the ways in which one format falls and another picks up. Definitely try to share as much code as possible between them all. Really forces you to separate concerns. There is no "GUI vs CLI". It's "GUI and CLI".