Meta | E6 | Virtual Interview + Rejection

I recently completed a Meta interview process that included:

Behavioral Interview: This went exceptionally well, thanks to mock interviews with former Meta employees that helped me understand exactly what was expected.

Machine Learning System Design:

Recommendation Problem: I designed a system to recommend interesting visiting locations.
Classification Problem: The task was to detect illegal item sales on MarketPlace.
Coding Interviews:

First Session:
I solved a merging intervals problem, but this time the intervals were represented as a linked list, and the output also needed to be a linked list. This is a hot topic question right now. I solved it optimally with some help from the interviewer.
The second problem involved finding the best fly and return days based on daily prices, which I solved suboptimally.

Second Session:
The questions were from Meta’s top 100 tagged questions. I did well on the first one, but for the second, I introduced a small bug that I couldn't catch.

Although I performed strongly in the behavioral and system design interviews, I struggled a bit with the coding challenges.

After a week and a half, I received a rejection email.