Context

Auto Layout is core to building adaptive iOS interfaces in Evernote, where the same screen must work across iPhone sizes, iPad, rotation, Dynamic Type, and split view.

Question

Explain how you would implement Auto Layout in an iOS app, using a concrete example such as an Evernote note editor header or note list cell.

Address these points:

1. How constraints define a view’s position and size.
2. How to create layouts programmatically versus Interface Builder.
3. How intrinsic content size, content hugging, and compression resistance affect layout.
4. How priorities and safe areas help resolve flexible layouts.
5. How you would diagnose ambiguous or unsatisfiable constraints.

Scope Guidance

The interviewer expects a practical engineering explanation rather than UIKit trivia. Focus on how the constraint system works, how you would structure a maintainable layout in code, and how you would debug common issues in a production Evernote iOS screen.