Odds are strong that your first web developer job will be the best programming training you'll ever have. That's because you'll probably end up working with some sort of legacy code. There's a slim chance that you'll be working on a project from the ground up, but it's more common with startups than established companies.
Usually your legacy code work will fall under a few categories: debugging, refactoring, or a mix of both. What makes this good for a junior developer is being able to work with other people's code. This is how you'll learn the difference between good code and bad code.
You'll gain the ability to read through any programming language and quickly figure out how everything works. The best thing about learning how to skim code is that you'll also find some really clever ways of doing things. There are some talented programmers out there that write eloquent code.
Typically new web devs want to come in and start a fresh project because that's what they have had the most practice with. One of the best things you can do to prepare for working in legacy code is to look through code in the developer tools. This gives you a short cut because it'll highlight the elements you're looking at so you can learn more about how the HTML and CSS interact.
The good thing is that most companies have more than one web developer so you'll be able to reach out to your co-workers if you need help. Senior web developers usually don't mind helping you out because they know how bad the legacy code can be.
That leads to another point about what to expect on your first job. You'll probably be talking to people more than you would expect, even if you work remotely. Most web development teams have some kind of communication software like Slack or Skype so they can stay connected in case a server goes down or people working on the same project have quick questions for each other.
Those stereotypes about developers not talking to anyone will go away faster than an ice cube in the middle of the sun. You'll be working within a group of developers and you'll have to talk to at least one of them every day. It's not a bad thing though. You can learn a lot from listening to more experienced developers work through the issues they're having.
Something else you'll realize on your first web development job is how little you actually know. It's one thing to know the concepts and understand how they are supposed to work and it's another thing to get them to work within existing code. You're going to learn things that you didn't know you didn't know and that's going to help make you a great developer.
Honestly, you're first job might not be that great. Of course there's a chance you'll love it, but the odds are strong that you won't. This isn't your last job though. This is your chance to get your foot in the door and start learning as much as you can as quickly as you can.
Do the best that you can and don't be afraid to talk to the other developers. They might be kind of weird, but they're pretty nice and they usually don't mind helping the newbies. Just remember that once you get through the legacy code horrors you'll be a much better developer because of it.
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