How do you get more knowledgeable on the business side of things as a developer? I'm pretty young in tech industry and whenever there are meetings with business people I tend to get lost due to limited knowledge on business domain.

Is it normal to have a colleague have his notifications slack turned off during work hours? Whats worst is we're collaborating on a common ticket, and when I send her a message, she doesn't even reply and few hours later she always apologizing and having excuses. I don't want to be disrespectful but this has been affecting my work.