INTERVIEWER: Thanks for coming in. Let's start with a quick coding exercise. Can you reverse a binary tree on this whiteboard? CANDIDATE: Sure. But first, can I see your production codebase? INTERVIEWER: (nervous laughter) That's... not how this works. CANDIDATE: Why not? You're evaluating whether I can write code. I think it's only fair I evaluate whether YOU can write code. Professional courtesy. INTERVIEWER: We really should focus on the exerci-- CANDIDATE: (already has laptop out, screen-sharing the company's GitHub) Oh. Oh no. INTERVIEWER: What? CANDIDATE: There's a file here called "utils.js" that is 4,300 lines long. INTERVIEWER: That's... legacy. CANDIDATE: There's a SQL query built with string concatenation. With user input. On your login endpoint. INTERVIEWER: We have a ticket for that. CANDIDATE: The ticket is from 2019. INTERVIEWER: We've been busy. CANDIDATE: There's a comment on line 847 that says "TODO: fix this before launch." Your app launched in 2020. INTERVIEWER: (sweating) CANDIDATE: You have no tests. INTERVIEWER: We have one. CANDIDATE: It's commented out. And it says "test that thing works" with no assertions. INTERVIEWER: ... CANDIDATE: I have one more question. Is the binary tree you want me to reverse in production? Because honestly nothing in your codebase suggests anyone here knows what a tree is. INTERVIEWER: We'll be in touch. NARRATOR: They were not in touch.