How do you handle keyboard appearance and dismissal?

Answer: Subscribe to keyboard notifications to adjust your layout when the keyboard appears or hides, so it doesn't cover your input fields.

Code Example:

class FormViewController: UIViewController {

    var bottomConstraint: NSLayoutConstraint!

    override func viewDidLoad() {
        super.viewDidLoad()
        setupBottomConstraint()

        NotificationCenter.default.addObserver(self,
            selector: #selector(keyboardWillShow),
            name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self,
            selector: #selector(keyboardWillHide),
            name: UIResponder.keyboardWillHideNotification, object: nil)
    }

    @objc func keyboardWillShow(_ notification: Notification) {
        guard let keyboardFrame = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect,
              let duration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double
        else { return }

        UIView.animate(withDuration: duration) {
            self.bottomConstraint.constant = -keyboardFrame.height
            self.view.layoutIfNeeded()
        }
    }

    @objc func keyboardWillHide(_ notification: Notification) {
        UIView.animate(withDuration: 0.3) {
            self.bottomConstraint.constant = 0
            self.view.layoutIfNeeded()
        }
    }
}

SwiftUI alternative: .ignoresSafeArea(.keyboard) or ScrollView handles it automatically.