I recently visited the Facebook campus to meet two of my design mentors. They told me that when they evaluate candidates they are looking to see that you are good at 2 of the following:
- Visual (Good UI Practices, Branding, Illustrations)
- Interaction (Interactive High Fidelity Prototypes made with Origami, )
- Product Thinking (Smart design decisions & planning)
They also said mentioning that you have front-end engineering experience and dev hand-off experience is a big plus point.
With respect to the portfolio review, one of my mentors said the biggest mistake he said candidates make is boring him with 15 minutes about user research and then showing only 5 minutes of the UI. He said everyone does that and they end up not paying attention after a point. He instead recommended a split of 5 minutes for user research and 7-8 minutes to showcase your prototyping. They really want to see how you iterate over your designs.
The reason they don’t care much about design is because Facebook is a company which ships product fas and they usually have dedicated user researchers. They want someone therefore who can leverage that research to build stunning visuals which remain consistent with their brand. In addition to that, he said that they sometimes design without research and use the usage metrics after the product is deployed to decide what to do next.
Also I highly recommend checking out http://cofolios.com and http://bestfolios.com to see the portfolio of designers at Facebook.
Hope this helps.