Once a teacher told me:
You don't need to know everything in software engineering but you should definitely know where to look for.
I document all the things I learn while coding. It's kind of a mini post. First I did it in Trello but know I feel more comfortable doing this in Dropbox Paper.
I'd usually include details about the reason I was doing that feature or why I was looking for that information to provide context, and also add code snippets, images, links to repositories or issues, quotes of people who commented on an important tip. Everything that looks important.
For example, one day I was building a feature that required PDF generation and I did it in the local environment with
wkhtmltopdf. Everything seemed to work fine in staging environment but the day I tried it on UAT it didn't work. It wasn't working at all in the cloud.
The issue was DevOps team uses Docker Alpine images and this meant I needed to take more care about the dependencies installed. The process to figure out how to solve this thing included terminal commands, GitHub issues, API calls to AWS S3, and more.
All of the findings are well-documented, with links, images, and more, in case anyone asks me or I get to be in a similar situation I'd know where to look for answers :)
That's kind of my process. Do you have one? If so, share it in the comments to learn new ways :)