Onsite Loop · Round 3 of 5  Technical Screen (Whiteboard Edition)
Time remaining 45:00

226. Invert Binary Tree

EasyTreesRecursionFamous
Given the root of a binary tree, invert it, and return its root. 
    4              4
   / \            / \
  2   7   -->    7   2
 / \ / \        / \ / \
1  3 6  9      9  6 3  1
Interviewer: Please think out loud. We are evaluating how you communicate, not whether you can do it. Also whether you can do it.
You may not use Google, documentation, your editor, an AI, or any tool you will use on your first day.

        
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Interviewer

    
✦ Claude has joined the interview(nobody invited it)

  

  
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Solved in 0.8 seconds · interview time remaining: 44:59 · signal gained: none

  


  

    

      
R . I . P

      
The Coding Interview

      
c. 1990s – 2026

      
“Please walk me through your thought process.”

    

    

    

      

      
Survived by
    
        
  • The whiteboard marker, dried out since 2019
    • 
        
  • 847 LeetCode problems, solved once and forgotten forever
    • 
        
  • Big-O notation, which the compiler never once asked about
    • 
        
  • Invert Binary Tree, the one that cost Homebrew's author a job, now vindicated by a language model
    • 
        
  • The candidate who built a real thing in a weekend and was never asked to show it
    • 
        
  • A take-home that “should only take two hours”
    • 
        
  • Hunger, tenure’s long-suffering rival, finally getting a hearing

      
“Small coding challenges once predicted success somewhat. AI now outperforms humans at these tasks.”
— Felix Rieseberg, Hunger beats tenure

      

      

      
In lieu of flowers, please send a weekend prototype that shows taste, empathy, and principled thinking.