If you’re not taking notes, then you should highly consider starting. It will help you remember and understand the topic more and it will give you a reference to go back to if needed. I think note taking is really important in the software developer field because having that reference to go back to is gold. Whether you just started a job or your having an off day, having the notes to remind you of what XYZ does or how to run the app’s tests is amazing.
My favorite note taking app on the Mac is Craft. I highly recommend checking it out. I recently switched from Obsidian to Craft because of the design. It’s still pretty easy to export the notes in Markdown if needed and it supports back-linking, which are 2 things I think a good note app should have. Obsidian is a good choice as well and because it stores all the notes as a Markdown file, you’ll have no issue getting those out of Obsidian.
☞ What is back-linking? It just means to link to another note in the database. It allows you to see other notes that might make sense. So I could link a note about core data to a note about cloudkit that way I know they relate to each other.