Lines of code is a terrible metric to assess engineers.

As a part of firing half of Twitter, Elon Musk parachuted in engineers he trusts from some of his other business interests, namely Tesla and Space Exploration.

These engineers reportedly decided to actively use the number of lines of code software engineers had written in the last three months as a measure of their employability.

This is at worst painfully ignorant and at best a hanger-on from 1990s style management thinking.

Broadly speaking you could argue if someone has written zero code for a long duration, that is worth investigating, usually they are off sick or frankly trying to solve problems elsewhere.

But on the day to day it can be a practically useless measure. For example a bad software engineer could decide to write 30x the code of a good one. Its trivial to bulk out any solution and make it 10x or more in size, whilst doing absolutely nothing better. This is part of the reason it a poor metric to use, its a fence post with no planks.

The awful approach taken fortunately had a beam of light shone on to it when the same people who did the firing then panicked when they realised they had fired entire teams of people they actually needed.

There are many ways to assess performance in software engineering, simply using Lines of code written , is not among them.