How many lines of code does an average Linux kernel developer produce per year?
Based on estimates of the value of the Linux kernel (around 2200 Million Euros in 2011), the size of the kernel (in 2011, version 2.6 was current, with a bit less than 20 million lines of code), and average salary of kernel developers (for Germany, one could estimate 60,000 - 80,000 EUR/year for a mid to senior embedded developer, you can go to kununu.de and look for salary statistics for larger companies like Siemens as a reference), one can estimate the lines of new code that a full-time kernel developer produces - less than 1000 lines per year:
value=2200000000
cost_man_year = 60000
lines_of_code= 20000000
person_years = value / cost_man_year
lines_per_person_per_year = lines_of_code / person_years
I get to 545 lines per person-year that way.
The interesting question is: You can obviously type that in in half an hour. What do these software developers actually do all day? ;->
Coding is the easiest part of the job and do not represent the main people activity.
Looking at the number of lines of code and thinking “they are only doing that” is like looking at any Mozart cues and thinking “he spent years to fill 50 pages of black dots?”.
Coding is like creating music. It’s not because you can write lines of code that the result will be a working solution.
You need to know your activity very well to be able to get the best from all the instruments you have in your hands.
Before coding any line, you had to THINK about the solution, find the best architecture, how to implement it without impacting in a negative way the product, detect the potential side effects, how to test in all the possible scenarios, how to maintain it, etc.
What you pay here is knowledge, experience, architect skills, coder, tester, troubleshooter, project management, devops, etc.
You pay highly skilled people who have the responsibility to not screw up all the servers infrastructure of the world, the brains of aircraft, cars, manufacturing tools, etc… And you don’t want them going elsewhere as the knowledge ramp-up of any newcomers could take years.
This is where the salary goes. People brain.
Yeah it’s like the engineer who wrote a 10000 dollar bill for exchanging a single screw to his enraged customer:
(It’s a whole story, I don’t remember exactly)