I haven't backed up my Mac in a long time. I know this is risky especially if GitHub (source code) or Apple (family photos) lose my data.
I decided today to select the Download Originals to this Mac option in Photos.app and then I'll back everything up.
I probably should back up my entire Mac to a service like Backblaze. The only issue with Backblaze is that it's $99 a year.
Then I'll at least have piece of mind that all my photos and code files will be somewhere.