Edit: I see I kinda went on a ramble
Indie development is easier if you have the time and skill
What is needed is based on the company, I would research their websites, social platforms and more to get somewhat of a sense of what they are looking for
This topic is welcome here, if you have lots of time, working as an indie game developer can be very beneficial, basically you build your own games and publish them to steam or you respectable app store, you build the games, in unity (or other platform, but unity is the best for this type of stuff) save as your selected platform, and it’s almost like uploading a YouTube video, there are fees to publish your games though:
Google Play - 1 Time, 25$ Fee
Apple Store - 99$ Yearly
Steam - 1 Time, 100$ fee
I’m pretty sure this is the numbers unless they were recently changed, but you can start your own business of game dev and build game after game to build up your portfolio and make you more likely to get hired by big studios. If part of your resume is “I have my own game development company with multiple published games, and am looking for something better” (Obviously don’t say that), then your chances of success can be much higher.
Just something to think about, I mean I am only 15 so I don’t have to much experience with jobs, but if you are confident in your abilities, id work on making your portfolio and resume as good as possible to show to the people who hire you
Some general tips, although I might not be to good at this, it could give you some pointers, hopefully somebody with more experience sees this post and can help you further.
Let me know if there is anything else I might be able to help you with!
Good luck!