I'm not going to specifically address Fabrice, but one thing I have noticed is that people who develop almost purely in one language, within a constrained application space, are able to become extremely productive because their knowledge and experience is very focused.
Consider for example someone who does nothing but C programming on a Linux platform. Say for example they build compilers. And say that's pretty much all they do. That person can become incredibly productive because they know the language and the tools extremely well.
Or maybe someone who writes computer games in Java. The only thing they need to know, and the only thing they have done, for many years is write graphics/games code in Java. That allows them to become extremely productive at writing games in Java. I've wondered about this in regards to Notch (Minecraft developer).
Now consider the modern full stack developer - there's a constant, never ending need to learn new things. New languages, new frameworks, HTML, CSS, JavaScript, ReactJS/VueJS/whatever, SQL, some backend language/Python/PHP/Java/C#, cloud operations EC2/Azure, Linux along with the many related toos like debugging etc etc. This sort of developer rarely comes up to mega expert level because they can't - they need to be very good at learning just enough to get the job done in a wide range of things. Likely they will have expert level in some of these technologies, but the point is that being able to dedicate your entire brainspace to only a few major technologies allows super productivity. The full stack developer is unlikely to be incredibly productive in one particular area.
The other thing that destroys my productivity as a full stack developer is hitting problems/roadblocks in some new thing that you need, but don't know well. This sort of thing can take days of problem solving, where an expert in that particular technology might be able to recognise and fix the issue in seconds. A good full stack developer must be very very good at problem solving because if you can't fix problems then you'll never get to write much application code.
On the other hand, a really good full stack developer should absolutely amaze you with their ability to build every single aspect of a large system including back end, front end, deployment and operations.
people who develop almost purely in one language, within a constrained application space, are able to become extremely productive because their knowledge and experience is very focused.
He mainly uses C and some JavaScript, but a look at all the things he's written suggests that he doesn't really focus on any one area; the first few projects on his page are:
It’s a great question but you also need to wonder about the opposite. Was Minecraft successful in spite of Notch’s Java development skills? I know of plenty of products that are successful despite their awful technical prowess. Is the multiplier about making money or technical skill because the discussion around it often mixes both or assumes the former comes from the latter.
Hm. I would argue that space of knowledge in both compilers and graphics (and maybe even JVM) is pretty huge. And it's a deep kind of knowledge, the hard one.
My point is that there is enough information to be always learning in all fields you've mentioned.
