What do junior developers need to know?

In "What do junior developers need to know?" I answer a programming question.

[mihailodukic]

In my country there are hardly any junior position . Mostly medior to senior . I know taking in a junior is a long term investment and a risk at the same time. I'm just looking at remote positions around Europe .

[MrValinterama]

Fredrik, you are awesome, just always remember that!)

[Finn-jppn]

Hi, Fredrick. I would love to have your take on how a new joiner can build trust and gain respect within a team.

I have less than a year of industry experience and have been assigned to a team containing mostly industry veterans.
Yet there is not much in the area of technical mentorship as my team members are evangelists whereas I am one of the two developers in the team.
For most development tasks that are assigned to us, we have the complete freedom to build it the way we want.
However, I am afraid there are times when our approaches to certain problems might come off as naive.
I hope to switch to a development team by start of next year and get some actual mentorship.

And thank you for these videos. You are one mentor that I keep coming back to whenever I feel lost.

[lalumierehuguenote]

Here's my question.
I am a junior dev and for a year started my career in a company where I do front end work. CSS and Javascript (Vanilla and jQuery). I also have to go over legacy code and work with a legacy language.

A year ago I was still at the "tutorial" stage. I have come a long way since then!

But my question in question is:
"will I be okay not having worked on React and new front end technologies when I switch company?"

[moslehmahamud]

**Summary:**

What junior developers need to know?
Junior developers need to know what senior developers knows :P