Data Scientists and ML Engineers – How do you keep track of what you have tried?

Hi all, I’m curious about how data scientists and ML engineers organize their work.

In your recent projects, how did you keep track of what you tried — preprocessing steps, model runs, or errors?

Did you have a process or system to look back at past experiments and learn from them?

Did you use any tools to help with this, like experiment tracking software? How did that work for you?

If you’ve ever struggled with this, what’s been the hardest part?