Suggest a full stack project.

Hey Guys,
This is my first post. Before I ask the question. Here is something about me:
I am working as a frontend developer since past 2 years. I am aiming to become a full stack developer, so i started learning NodeJS. I have built 2 projects:

• Task Manager API (Users and tasks)
• Chat application using socket.io

Github: https://www.github.com/arpitmalik

I need project ideas that I can build on MERN stack. One of the idea I thought of is a URL shortner.