HACKER Q&A
📣 sberg08

I failed FAANG interview because I didn't know Binary tree?


Role was for Frontend engineer. There were 6 interviews (1 hour each). First 5 interviews went well. In the last interview, SDM asked me to explain binary tree and how to demonstrate it with a solution. It costed me the interview.


  👤 anyfoo Accepted Answer ✓
Sorry to hear. Binary trees and related concepts (binary search, for example) are super useful and relatively basic, so they can usually be found in any introduction to algorithm and data structures. If you want to try again, do some studying of that. It will definitely help your programming skills in general!

This, by the way, can easily be the kind of concept that you don't think you need until you learn about it, suddenly figuring out that you've been writing very inefficient code before.


👤 clintonwoo
You need to dedicate significant study into data structures and algorithms with lots of coding challenges (leetcode-esque) to pass these interviews. Even some world class programmers will fail the interviews, that's how they've been designed.

I think it's quite a reasonable expectation to achieve a high paying job. It's just a shame that it's not necessarily related to the day to day work, not will your prior work experience help much.


👤 random_coder
Best to forget about that interview and focus on future ones. Frontend engineering doesn't mean you can ignore performance issues in your programs. Binary trees are a very useful data structure to know in general. Ordered collections in many languages' standard libraries are internally implemented as balanced binary trees. It's good to have at least a high level understanding of this data structure.

👤 Raed667
Unfortunately, even if you won't be using it during your actual work, data structures and algorithms is still part of the interview process.

If you don't feel like going on a crusade to change the whole interview system, get yourself "cracking the coding interview", learn the basic stuff: linked-lists, trees, hash-map, search, sort, big-o

Honestly there isn't that much you need to know.

and just bite the bullet.


👤 cowvin
Yeah, that's rough, but you really should know what a binary tree is if you want to be a software engineer. It's probably a good idea to study data structures and algorithms a bit more.

👤 sys_64738
Didn't you learn about BST during your Computer Science undergrad?

👤 aristofun
Just found a new google killer please and tell this story in the interviews.

(it’s sarcasm people, why downvoting?)


👤 beardyw
Sad thing is you might have been the best candidate. Just didn't know the secret handshake.