So i found the solution! If we want to customize our button or view or something else view gradient background if we use only layout and don't use CGRect for button or UIView doesn't matter frame of our UIView is gonna be 0, 0, 0, 0 therefore gradient.frame = (0, 0, 0, 0) but its only in ViewDidLoad method:) if we will use viewDidLayoutSubviews() method, we will get updated size of our button or view and therefore we have to do override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews... gradient.frame = view.bounds }