So. I'm not sure why? I try to refrain from diving into open discussions like this.
But, somehow I made a post on Quora when someone asked "Is HTML, CSS, Javascript, Node.js, and SQL, enough to be a full stack developer?" It's not really a great question. Maybe a better question might be "How much experience do I need to become a [name a stack or platform like: React or Node] full stack developer?
I think the short answer is to go on LinkedIn or Indeed, look up full stack developer, and see what is listed for requirements under Job Descriptions. It is sort of a catch-can topic for me because I can write a whole new post on "hiring" someone and Job Descriptions in the IT world. Hopefully sometime soon, I'll write a post on those subjects.
Below is my answer I posted. I thought I'd keep it here since I did write it. You can see the link below and what others have posted as an answer. What do you think, in a short description constitutes a full stack developer?

I think many people, even often employers, are missing the overall view. And yes. Some of the key points here brought up are valid. Full stack web developer IS in fact a lifestyle. And yes. Keeping up with the latest technologies IS a part of the job, BUT often loses sight of what a full stack developer really is.
1. The dawn of time. Full stack developer is another term or title. It really only became popular over the last 3–5 years give or take. For someone who in fact spent time learning Flash and Actionscript during it’s day, it is relatively new. I know. Buzz words are just that. They don’t necessarily mean squat. Full stack developer was a term thought up to describe someone who has a role and is capable of doing “the full stack.” Meaning Front-end work. Programming somewhat. Back-end work. And database. How these ALL work together and how to set up the entire stack. Mostly it had reference early to LAMP stack initially but lately it refers to any stack. Node MERN React even Python Go Ruby mostly anything with a database. How to set it up, how to maintain it, how it works. Thus stack.Anyone prior to the term might get frustrated simply because if you already worked the web there is a good chance you already were a full stack developer. Front back DB. Working a LAMP stack for example was not uncommon. But yes. There are just front end people. Or back end people. or just database people.
2. What is a full stack developer? Well, as stated before it could mean someone who knows any of the latest current stuff used. You could be a MERN stack developer, or a LAMP stack developer. Learning to code in the things you listed is a good start. That’s HOW it all starts. You learn to code. You have to learn how things work together. You learn more and before you know it you are working with the stack. Full stack developer is a lifestyle because after you work these stacks you gain knowledge. It’s really more of a Web Engineer. A good Web Engineer who has worked with these stacks knows how logically these things work, what to look for, how to set them up, etc.So yes. Technology you always have to learn. But many things repeat themselves. SSL, setting up servers, code arrays strings DB calls queries etc have some kind of a standard pattern. So, over time a good Web Engineer or auto mechanic for example will know how logically everything is supposed to work and what to look for. Thereby, learning new technology faster than someone starting out. Everything in the past that you learn many times reinvents itself in the future. Javascript, PHP, MySQL are nothing new.
3. Do you need to learn new technologies? Yes. Can you know everything? No. It’s a never ending cycle. What IS important is that “on-the-job” you have enough experience to : Set up a Stack, install and maintain. Troubleshoot a stack, and make upgrades to that stack. Mainly many times a full stack developer has a deep understanding of all this and has the ability to troubleshoot and fix issues that occur during the life cycle. The best way to learn is through “doing” or being in situations that naturally occur or become problems on the job. Also, being able to just about handle any situation, whether it be troubleshoot a database, merge, migrate data. Troubleshoot code or write code. Write or design front end code. And make the stack work well. If you can handle a diverse set of issues without any advanced notice on a fly, you can definitely fall into the full stack developer title, which originally is what people where referring to. Having a full diverse knowledge of how the whole thing works. And it doesn’t stop there. Server management, client relations, working with other team members, deadlines, customer relations, things that don’t work.
4. Don’t forget also that many things it doesn’t matter what stack they carry across such as GIT, command line, building a development server or environment, HTML, CSS, etc. Often being a developer branches off into being a System Administrator, Database Engineer, Programmer, Front end Developer, or Software Engineer.You can’t know everything. But you should know how things work. How to set up an environment or the full stack, how to troubleshoot it, how to fix things, how to migrate or upgrade it, and how to design, run, and streamline a project on that on whatever stack you are running and bring it to production. Knowing how to work calmly, back things up, have insane patience and persistence without defeat, a constant desire to learn, and work past issues that break your stack or make life difficult is essential.But yes, it all starts with some code and tying it all together.Employers should be focused not on making some shopping list and lightly adding everything to that list, but rather, finding someone who is going to solve their problems, customize their case scenario, and make it work. Meaning a diverse background and a persistent desire to wire everything together seamlessly, correctly, for the right application. Realistically, you can spend over 5 years full time on each language, platform, and stack. The learning curve on these technologies are endless. (node, react, javascript, php, mysql, Go, Ruby, Python, C++, .NET, vue, linux, server management, webpack, npm, gulp, kubernetes, jenkins, you name it.) It’s like saying: “Do you know Spanish?” It’s not common these days but have you ever been a bookstore, gone to the computer section and picked up a book on any of these? Five dollars says it’s as thick as a brick, over 350 pages and each one says beginning, intermediate and advanced.