Do I have to learn mySQL or something similar if I want to become a Full Stack developer? I assume I have to have at least some knowledge of databases.

You should definitely learn about databases, there are two popular types NoSQL (e.g. Mongo, DynamoDB) and SQL based (e.g. MySQL, Postgres).  You'll want to learn about how this data is served e.g. JSON or GraphQL

A full stack developer should be able to build a moderately complex application and should as a minimum have knowledge of the following areas.

Deployment (Cloud based, AWS, Google Cloud Platform, Docker, CI/CD etc.  There is a LOT to learn in this area)
Databases,
Backend - Microservices, FaaS, CMS, REST, GraphQL servers etc
Frontend - HTML, CSS, JS (ES6, React), A11Y, UX patterns
General - You should know how to write automated tests for your application with unit/integration/end-to-end tests, you should know how HTTP works in detail - what do the status codes mean, what about headers? cache-control etc etc.  You should also have a good grasp of security - how do you handle authentication.  You'll need to learn about capturing logs for front and backend systems (CloudWatch, Kibana, Grafana, SpeedCurve for performance monitoring).  You'll need to know how Cookies work as they're used extensively.

I've said this before and I'll say it again though:  If you're looking for your first role then going straight for full stack is setting the bar very, very high.  Most full stack developers have been working professionally for years before they really attain the level of knowledge to market themselves in this way.  Of course the choice is yours but you really are giving yourself a mountain to climb which is made much harder if you aren't already working full time as a developer (Working with others you'll learn much faster than doing online courses alone.)
I don't know anybody who's a full-stack dev that learnt it all upfront, they all got a job in a specialism and branched out.

It's worth noting that you'll make things a bit easier if you focus on JavaScript as you can use the language on the client and the server rather than having to learn multiple languages.

Edited February 6, 20206 yr by rbrtsmith

What a great reply, Robert!

The problem is, I've already subscribed to the Treehouse Full Stack JavaScript Techdegree course (just recently resumed it).  Will they not hire me with this degree or do I have to learn all these things you listed in addition (I don't think all of them are taught in this Techdegree)? Where do I go to learn all these? If I remember correctly, you told me Treehouse is all I need to get a job.

I'm guessing Treehouse will teach you a particular database so that you can follow along. Stick with whatever they teach you for now because the rabbit hole goes very deep when you start getting into this sort of stuff.

Nobody cares about certificates or whatever when they hire you.  You'll need a CV that is appealing and you have gained some experience in the tech stack they use.  Essentially they want to see you have the ability to add value, and for a junior the main thing we'd look for is enthusiasm and ability to learn.

The bar to entry for frontend developers or backend developer is considerably lower to a full-stack developer.  Perhaps do the TreeHouse course then focus on the area you enjoy the most - backend or frontend.   Once you have a job spend a few years learning and then you might be in a better place to learn "the other side" so to speak and become a full-stack dev.  Bear in mind this isn't the only progression.  I know frontend developers who do little to no backend and still get paid a fortune and are very senior in the business.

When I said Treehouse is all you need I meant that I just did their frontend course and used what I'd been taught to build some examples to demonstrate to employers.  I didn't get any certificate for the course it was just a load of focused tutorials which for the most part were very good.  I don't know if the full stack course goes into enough depth given the entry level for full stack developers is much higher.

Edited February 10, 20206 yr by rbrtsmith

I understand. Thanks, Robert.