Phone Interview:

As many have commented, it was largely standard.

Onsite Interview:

Included 3 whiteboards and 1 behavioral.

Many people have commented that the onsite interview for FB DE includes Product Sense, SQL, and Python. However, for me, the focus was mainly on Data Structures and Algorithms, followed by Product Sense.

All three areas are focuses of the interview and have equal probability of being asked in depth. So, do not ignore DS Algorithms.

There were a few hypothetical questions, but those were for the end, assuming one completed the DS Algorithms questions first.

I was not asked any SQL questions.

Object-Oriented Design for a Data Set:

Questions on Trees.

No Questions on Product Sense, Data Modeling, or SQL.