So... I'm working on re-writing a book right now (well, in fairness, by "right now" I mean "I put it down for a year and am just getting back into the revision) which is being told from the POV of 4 different chraacters. It's also currently more than 100,000 words long and I know that publishers have flat-out told me that this is way too long for something in its genre, so changes will have to be made. Still, 4 POVs, 100k words, that's about the size of, I think points of view changes.
One thing I think a lot of beginning writers get hung up on is this idea of character being "oh man, I have to find a way to include a backstory here" or "I need some kick ass descriptions". This is false, I think. Character is action. I'll repeat that in bold type because it's important. Character is action. People aren't going to remember your character because you wrote a couple paragraphs about how he fought in the battle of Zentronobia with just a phaser and a Model III lightshield. They're going to remember that thing he did to the other people in the story.
This is not to say you should skimp on backstory at all. Write it all out by all means. One thing I did with this latest book is I put together character bios for all the mains: a quick summary of their strengths, weaknesses, and physical description, but also a description of their upbrining, demeaner, work and social lives, and so on. None of this is in the actual writing, although obviously I draw on it quite heavily. If this sounds like "overwriting" and committing too many words to something that's not going to be in a final draft, consider this: chances are, nothing you put down into that first draft is going to make it into the final draft anyway.
This solves two separate but related issues:
You now have a character with information you can refer to when you're writing the story. Of course, you can always change that information down the line as you realize more about who the character is and so on, but the important thing is that you've got a vivid picture of this character in your head.
You will feel far, far less compelled to write in backstory which only needed to be there for your own edification because, well, you've already written that backstory. You'll come to a point where you say "how much does my audience need to know about this person" and you'll be able to answer that concisely.
I've heard this called the "iceberg" method of storytelling, although TBH I don't think that a 1k-2k word character bio quite counts as an "iceberg" when you're writing 60,000 or more words of narrative about said character. It's more like the "ocean liner" method; there's a lot to be seen above the waterline but there's a little bi below as well.