I went through a few repos and the result was a weirdly consistent 30-45 LOC(sans tests) daily for a 2-3 person team - at least on the front-end.
Since then I'm sceptical of opinions saying that a 1500 LOC+ project could be put together "within a weekend".
Not saying it doesn't happen, but good projects of this sort have to be rare.
Sitting at a desk for 6-8 hours every weekday with an editor in front of you has this weird demotivating effect. Add to that all the unit tests (and general need for stuff to actually work well the first time), documentation, and not being able to just run off and build what ever you feel like and you get closer to 30-45 LOC.
For a new project, 1500 LOC within a weekend sound possible if the goal is to quickly produce some kind of proof of concept. You would probably spend the following days on redesigning the whole thing, though :)
The "sans tests" metric is in my opinion some kind of cheating to keep the number small.
Let me explain: when I was younger, I was already immensely productive as a programmer. But because I was young and naive, I did not care about testing etc.
When I look at code that I produce today in my free time, I observe that the ratio between test code and normal code is about 6:1. It is similarly hard to produce good test code as it is to produce "ordinary" code.
So by demanding that the code is well-tested, we need a lot more code to solve the same job. If I multiply your upper bound of 45 LOC by my factor of 7 (= 1 + 6), I obtain 210-315 LOC/day. This is much nearer to my experience of 400-500 LOC per day. The remaining difference can be plausibly explained by experience of other team member, time for communication in the team, time for communication with customers, overhead demanded by management, ...
But I agree - a good test suite is going to be much larger than the code it's testing.
> 1. They have no idea what the average developer actually is.
> 2. They are lying to make it sound like they were elite when they were a freshman in college.
Concerning 1: they might really be living in some kind of filter bubble of really smart people. Smart people often attract and are surrounded by smart people.