This is a great idea, which I believe I've seen Julia mention in the past, and I definitely agree that this can help with making sure you remember what you've done! In a previous job we had 'monthly status reports' which were an overhead at the time, but when leaving the job (as my placement year was up) I was able to look back at all the stuff that I'd achieved.

I like to get microfeedback from colleagues, so throughout the year I'm getting bits of feedback on things I've worked on, so for 6-month checkins I've got lots of evidence.