I have seen a lot of similar questions, but I'm looking for a specific solution and I don't know if any of the common programs offer that solution or which of them would be best suited.
I have a PC, a laptop and an external hard disk. In the future, I will have to switch back and forth between working on my PC and working on my laptop. I want to make sure that whenever I have to switch devices, I have the exact same files on both computers, and I want to do it entirely without internet access using my external hard disk as the "middle man" so to speak.
The biggest hurdle for me is the kind of files I have to work with. All of my projects have node_modules folders, which are freaking humongous... around 200 MB. Doesn't sound too bad, but multiply that by a few dozen, and it becomes a problem. Thankfully, those folders are entirely auto-generated with npm, thus I don't have to carry them back and forth. Of course, with my dream file syncing software, I would be able to mark those folders as "NEVER SYNC" and not have to worry about the software scanning a million files it doesn't need to copy.
Do any of the file syncing programs offer that functionality? Besides that, I just want to make sure that all folders stay the same across devices: the newest changes to a file are carried over to all devices, new files are copied to all devices, and deleted files are deleted across all devices.