For Facebook, the product design type questions would be in the produce sense round. The questions you get might be:
- Design a social travel product for Facebook
- Design a jobs product for Facebook
- Design a product to help users find a doctor on Facebook
There are other companies that have physical product design questions like “design a blender for a blind person” which in my opinion is much harder.
For Facebook, I would start by using every single product they have and familiarize yourself with features. This means, Facebook, Instagram, WhatsApp, and Oculus. Then in your interview, you’ll have better product intuition and make connections across products.
Here’s an article with a framework to use: https://ayanh.medium.com/facebook-product-sense-interview-what-is-it-and-how-to-prepare-bda3c5197f3c