Just how many developers are there in the world? According to a study earlier this year from SlashData, there are 19 million. However, 13 million are professionals... meaning there are a lot of "casual coders" out there.
The report taps five distinct sources (GitHub, Stack Overflow, npm, U.S. Labor Statistics, and EU28 Labor Statistics) to arrive at its conclusion. Though it admits some of its methodology is “ambiguous,” SlashData attempts to distill who actually codes full-time versus those who just tinker.
One major (and ambiguous) threshold is involvement in a “substantial coding project,” which (SlashData admits) excludes those who may code as part of their job function if they only do "tiny" things. In theory, this eliminates those who maybe
use markdown write a bit of code where there’s no macro or automation in-place from those who write actual applications or develop websites. It also excludes inactive developers (you know, the ones who have moved on to podcasting and no longer write any actual code).
But that doesn’t exclude everyone who doesn’t code as a primary job function. The report embraces hardcore hobbyists and students:
We do count developers who code purely as a hobby or who are still studying the field, without being professionally involved in any software area. Our survey data over the years is fairly consistent on this, with pure hobbyists/students representing just under a third of developers. We estimate that there are 6M hobby developers and students at the end of Q4 2018, in addition to the 12.9M professional software developers.
In total, the global developer base has grown 21 percent in 2018; at this pace, SlashData says there will be 45 million globally by 2030. If the same two-thirds ratio holds true, that also means we’ll have nearly 30 million professional developers in 2030. It could also be far more; SlashData attributes the continued rise of professional developers to the increased global availability of internet connectivity.