Agreed. I would also add, I don't think frontend vs backend accurately describes how skillsets are clustered anymore -- especially with JavaScript's increasing ubiquity.
I would cluster skillsets into: ops, development, and design.
Ops: making things highly available, logging, performance monitoring, reliability, deployment scripts
Development: Writing code on both frontend and backend.
Design: Visual design and CSS/HTML
Most developers I've interacted with at various companies write both APIs in the backend and user facing UI. In my experience it's becoming increasingly rare that a frontend developer doesn't also write backend code.
They typically aren't very good at making their apps deployable and highly available, and they also aren't very good at making things look good with CSS. Sure they can do it, but it isn't their specialty and it would be quite a learning curve or it just takes them much longer than someone who does just that.
When hiring people, I like to find people who are strong individually in those 3 areas (ops, programming, design). I don't try to find programmers who can do ops or design. I don't worry so much about a frontend engineer being able to do backend work and vice versa, the crossover is generally smooth and interchangeable.
It is generally easy to find ops, and programmers who specialize and are talented. Designers who can do visual design and code it up are a bit rarer, so sometimes it is needed have 1 person do design and another person code it up.
Also, a very senior person is obviously going to be stronger in each of those areas, so full stack is highly correlated with working experience.
I think the crossover between frontend and backend is less effective than you imagine. Generally a backend dev writes horrible frontend code and viceversa.
A very senior backend person will probably know many things about ops and frontend, but probably not about design.
A very senior frontend person will probably know a lot about design, UX and have a good enough experience with backend, but is probably not going to implement good ops practices.
In the React / Node world I haven't seen this to be true. I can imagine it being more so if the languages and tooling are different like in the case if someone was doing Java backend Angular frontend.
Same with Vue. I used to be more back-end, but frameworks like Vue and React make front-end feel more like traditional back-end, and are a joy to work with.
I'd separate the client side scripting and styling / layouts, actually. While JS and JS frameworks are fun and enjoyable to work with, and I can architect the JS stuff well to make maintainable code bases, CSS is still a mess for me. Though getting better at that as well. Flex-box and CSS Grid changes the game completely from using floats to do layouts.
> so sometimes it is needed to have 1 person do design and another person code it up.
Honestly, even when it is the same person doing both, I feel like it is best practice to do these activities separately anyway. As in, literally on a different day, with a different mindset.
If you design an application's looks and UX according to how the code 'should' work, particularly backend code (DB queries and endpoints etc) you'll most of the time end up with something that's suboptimal for the user without being able to see it - because you have this very detailed mental model of the system behind the curtain and it's 'obvious' that things should work in this way or that in strict accordance with how that system is organised - whereas the user knows / cares nothing about these things and wants things organised in a way that's more intuitive to them.
I would cluster skillsets into: ops, development, and design.
Ops: making things highly available, logging, performance monitoring, reliability, deployment scripts
Development: Writing code on both frontend and backend.
Design: Visual design and CSS/HTML
Most developers I've interacted with at various companies write both APIs in the backend and user facing UI. In my experience it's becoming increasingly rare that a frontend developer doesn't also write backend code.
They typically aren't very good at making their apps deployable and highly available, and they also aren't very good at making things look good with CSS. Sure they can do it, but it isn't their specialty and it would be quite a learning curve or it just takes them much longer than someone who does just that.
When hiring people, I like to find people who are strong individually in those 3 areas (ops, programming, design). I don't try to find programmers who can do ops or design. I don't worry so much about a frontend engineer being able to do backend work and vice versa, the crossover is generally smooth and interchangeable.
It is generally easy to find ops, and programmers who specialize and are talented. Designers who can do visual design and code it up are a bit rarer, so sometimes it is needed have 1 person do design and another person code it up.
Also, a very senior person is obviously going to be stronger in each of those areas, so full stack is highly correlated with working experience.