Long ago, he joined a company fresh out of college that pretty much measured dev productivity with number of lines written. He quickly realized that it was a red-flag, but jumping ship so soon was going to be hard to explain on a resume.
So he basically started writing code in two stages using a codegen tool: something high level not under source control that would generate extremely verbose code that would be checked-in.
Inheritance? Polymorphism? Interfaces? Not in the generated code for sure. Duplicated code all over. Other engineers were furious but management kept defending him "he's just a junior and his metrics are off the charts, you guys just can't keep up with him".
Three promotions in 18 months and jumped to a FAANG not long after.
Sorry to hijack your comment, but I would like to say:
There are many, many good reasons why someone would want to quit a job after only a short period of time at a company (harassment being an obvious one). It took me a long time to realize this fact, and stop viewing a quick departure as a potential red flag and also stop asking questions like "Why are you looking for a new role?"
Someone leaving a toxic environment really doesn't want to spend any part of the interview talking about the past; they want to show you they will be a valuable member of your team, while also learning if your company is one they want to work for. We should all consider that the next time we are reviewing resumes and interviewing candidates.
Nobody expects someone to get married after a couple dates.
I do this unironically. Mostly for producing unit tests from more sophisticated testing tools. I'm not silly enough to tell my coworkers that's what I'm doing, though.
Curiously, it's desirable to both have many PRs and few revisions - but also large ambiguous and difficult PRs. Obviously this can thus be gamed.