You trained the model. The notebook runs. The demo works. You push it to a teammate, and forty minutes later you get the message every engineer dreads:
"Hey, I'm getting a CUDA error. And torch won't import. And what version of Python is this?"
And you say the six words that have haunted software since the dawn of time:
"But it works on my machine."
Here's the uncomfortable truth: "it works on my machine" isn't a defense. It's a confession. It means your code depends on something living on your laptop that you never wrote down a Python version, a system library, a CUDA toolkit, a stray environment variable, a model file sitting in ~/Downloads.
