Depending upon where you grew up, eye drops (both medicated and non) are supplied in single use droppers that have twist off tops that look exactly the same.
Personal experience and knowledge does not map perfectly to others experiences.
Just went through this process myself with a similar rag-tag collection of snippets. I used the zettlekasten process and a plug-in for visual studio code to help with the organization of said information.
Pardon the question: What skills are you looking for that define "mid level software engineer"? I'm a long-time engineer at a single company. I've been more and more tempted to strike out elsewhere as I feel like there is nowhere else for me to move into position/pay wise where I am. I need help to determine how to frame the skill level that I have and/or where to focus on so that I can claim/apply with a certain level of skill.
There is a wasteland of blogspam around the topic of getting started with ML and it’s hard to know what is useful at the beginning.