My Unify Tech iOS Developer Interview Experience (August 2025)

In August 2025, I interviewed for an iOS Developer role at Unify Tech.
The interview was a single technical round, and it mainly focused on core iOS fundamentals, Swift concepts, and real-world understanding rather than tricky puzzles.

Below, I’m sharing all the questions that were asked, along with clear explanations based on practical iOS development experience.

1️⃣ Copy vs Retain in Swift

In Swift, memory behavior depends on value types and reference types.

• Copy → Used with value types like struct, enum
• A new copy is created when assigned or passed
• Retain → Used with reference types like class
• ARC increases the reference count instead of copying

👉 Swift follows ARC (Automatic Reference Counting) to manage memory automatically.

2️⃣ Atomic vs Non-Atomic in Swift

Swift does not directly support atomic properties like Objective-C.

• Non-atomic (default in Swift)
• Faster
• Not thread-safe

Thread safety is achieved using:

• GCD
• Locks
• Actors (Swift Concurrency)

👉 In Swift, we handle concurrency at a higher abstraction level instead of atomic keywords.