Those criticisms aren't about mere bugs, but a bloated over-engineered iOS apps with far too many classes (18k back in 2015) [0]. The Android app was also previously notorious for patching Dalvik at runtime to deal with the huge number of Java methods [1].
Granted, perhaps things have gotten better in the last five years.
It's certainly possible for an enormous engineering company to have poor code quality or poor engineering practices, despite having a high interviewing standard. And a criticism of Facebook need not be a criticism of all companies that interview by Leetcode, for instance no one here is criticizing Google, Amazon, or Apple, and all have better reputations for code quality.
Granted, perhaps things have gotten better in the last five years.
It's certainly possible for an enormous engineering company to have poor code quality or poor engineering practices, despite having a high interviewing standard. And a criticism of Facebook need not be a criticism of all companies that interview by Leetcode, for instance no one here is criticizing Google, Amazon, or Apple, and all have better reputations for code quality.
[0] https://www.reddit.com/r/iOSProgramming/comments/6upeu6/how_...
[1] https://www.facebook.com/notes/facebook-engineering/under-th...