There is an ongoing appwrite + DEV hackathon. And I wanted to take part in it but I had never used appwrite before. I was worried that learning appwrite will take a lot of time, plus I came to know about this hackathon very late so I may not be able to submit anything in this hackathon. But appwrite was really easy to understand and implement. I thought that making a photo gallery will teach me the core concepts of appwrite plus I can submit it to the hackathon.
After reading through the docs and 30 Days of Appwrite blog posts, I finally finished the site with bare minimum functionality. :D

Github repo: https://github.com/PlabanKr/photoz