Memory Management in iOS Apps

Context

Memory management is a core part of building stable iOS applications. Interviewers ask this to assess whether you understand object lifecycles, performance trade-offs, and common causes of leaks or crashes.

Question

Explain how memory is managed in iOS applications. In your answer, address:

1. How ARC works and what it does automatically.
2. What causes retain cycles and how to prevent them.
3. The difference between strong, weak, and unowned references, and when to use each.
4. How you would diagnose memory leaks, excessive memory growth, or app termination due to memory pressure.

Scope Guidance

The interviewer expects a practical engineering explanation rather than compiler internals. Cover the object ownership model, common pitfalls in UIKit/Swift code, and the tools and coding patterns you would use to keep memory usage under control.