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iOS Interview Question (Part 9)
3 min readFeb 7, 2025
- what is Vertical and Horizontal slicing in swift
- Explain generics, protocol constraints, and type safety.
- What is Property Observer? Write an example.
what is Vertical and Horizontal slicing in swift
🔹 1. Vertical Slicing (Feature-based Approach)
- Definition: Breaking the app into independent, self-contained features (end-to-end functionality).
- Focus: Each slice contains UI, business logic, and data for a specific feature.
- Goal: Deliver small, working features instead of layers.
🛠 Example (Vertical Slice: Login Feature)
A Login feature would contain:
1️⃣ UI Layer (LoginViewController.swift
)
2️⃣ Business Logic Layer (LoginViewModel.swift
)
3️⃣ Networking Layer (AuthService.swift
)
4️⃣ Data Layer (UserModel.swift
)
💡 Benefits:
✅ Encapsulation → Each feature works independently.
✅ Easier Testing → Unit tests cover individual features.
✅ Faster Development → Teams can work on features separately.
📌 Code Structure for Vertical Slicing
📂 Features
├── 📂 Login
│ ├── LoginViewController.swift
│ ├── LoginViewModel.swift
│ ├──…