They look to see that your credit score is decent, you have steady employment and would be able to afford the apartment. They also look to see if you have any evictions or foreclosure on your file.
Before renting to someone, they would look for delinquencies, unpaid debts, defaults, too much debt, or any other indications that you will not be able to pay your rent every month.
They look for a history of not paying debt or paying late on financial obligations, since this implies you may not pay your rent or will pay it late to them.
Available balance in your account because they check whether you have enough amount to pay them or not. Also, they will check your backlogs which gives the information about your paid history to last contractor.