https://github.com/shobhakartiwari/ios_coding_interview
A comprehensive collection of real-world technical interview questions and scenarios from leading technology companies. This repository helps developers prepare for coding rounds, system design interviews, and technical assessments.
https://github.com/shobhakartiwari/ios_coding_interview
app coding-challenges codingchallenges interview ios mobile-app tecnicaltest
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A comprehensive collection of real-world technical interview questions and scenarios from leading technology companies. This repository helps developers prepare for coding rounds, system design interviews, and technical assessments.
- Host: GitHub
- URL: https://github.com/shobhakartiwari/ios_coding_interview
- Owner: shobhakartiwari
- Created: 2024-11-27T04:54:38.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-11-27T05:49:38.000Z (over 1 year ago)
- Last Synced: 2025-09-20T09:46:22.290Z (6 months ago)
- Topics: app, coding-challenges, codingchallenges, interview, ios, mobile-app, tecnicaltest
- Homepage: https://www.linkedin.com/in/shobhakar-tiwari/
- Size: 8.79 KB
- Stars: 10
- Watchers: 1
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# 🚀 Company-Wise iOS Technical Interview Questions
- 🎓 Welcome, I’m Shobhakar Tiwari working in the USA 🇺🇸 and currently in the Central Standard Time Zone (CST). I enjoy writing blogs on Medium, contributing to the iOS dev community, and sharing iOS interview questions to support junior and senior iOS developers alike.
- [If you preparing for iOS Interview feel free to connect for mentorship.](https://www.linkedin.com/in/shobhakar-tiwari/)
- A comprehensive collection of real-world technical interview questions and scenarios from leading technology companies. This repository helps developers prepare for coding rounds, system design interviews, and technical assessments.
## **Walmart Mock Interview Question**
- [Walmart Interview Question](#walmart-interview-question)
- [Problem Statement](#problem-statement)
- [Technical Requirements](#technical-requirements)
- [Implementation Guide](#implementation-guide)
- [Code Solution](#code-solution)
- [Technical Deep Dive](#technical-deep-dive)
### Problem Statement
**Real-time ETA Tracking in Ride-Sharing Application**
Design and implement a feature for a ride-sharing application that displays real-time ETA (Estimated Time of Arrival) updates for drivers. The system must efficiently handle periodic network requests while maintaining optimal resource usage and user experience.
### Technical Requirements
1. Implement periodic ETA fetching (10-second intervals)
2. Handle view lifecycle management
3. Implement proper network request management
4. Ensure thread-safe UI updates
5. Implement memory leak prevention
6. Handle error cases and network failures
### Implementation Guide
#### Architecture Components
- **Timer System**: Manages periodic network requests
- **Network Layer**: Handles API communication
- **UI Layer**: Updates and manages view state
- **Error Handling**: Implements retry mechanism with exponential backoff
#### Key Considerations
- Resource optimization during screen transitions
- Thread safety in UI updates
- Memory management
- Network failure resilience
### Code Solution
```swift
import UIKit
class ETAViewController: UIViewController {
// MARK: - Properties
private var timer: Timer?
private let etaURL = URL(string: "https://api.example.com/driver/eta")!
// MARK: - Lifecycle Methods
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
startFetchingETA()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
stopFetchingETA()
}
// MARK: - Private Methods
private func startFetchingETA() {
timer = Timer.scheduledTimer(
timeInterval: 10.0,
target: self,
selector: #selector(fetchETA),
userInfo: nil,
repeats: true
)
timer?.fire()
}
private func stopFetchingETA() {
timer?.invalidate()
timer = nil
}
@objc private func fetchETA() {
let task = URLSession.shared.dataTask(with: etaURL) { [weak self] data, response, error in
guard let self = self else { return }
if let error = error {
print("Failed to fetch ETA: \(error)")
return
}
guard let data = data else { return }
if let eta = self.parseETA(from: data) {
DispatchQueue.main.async {
self.updateUI(with: eta)
}
}
}
task.resume()
}
private func parseETA(from data: Data) -> String? {
return String(data: data, encoding: .utf8)
}
private func updateUI(with eta: String) {
print("ETA Updated: \(eta)")
}
}
```
### Technical Deep Dive
#### 1. Network Failure Handling
Implement an exponential backoff strategy for handling network failures:
```swift
private func retryRequest(after delay: TimeInterval) {
DispatchQueue.main.asyncAfter(deadline: .now() + delay) { [weak self] in
self?.fetchETA()
}
}
```
#### 2. Thread Safety Implementation
Ensure UI updates occur on the main thread:
```swift
DispatchQueue.main.async {
self.updateUI(with: eta)
}
```
#### 3. Request Cancellation
Implement proper request cancellation to prevent resource leaks:
```swift
private var currentTask: URLSessionDataTask?
@objc private func fetchETA() {
currentTask?.cancel()
currentTask = URLSession.shared.dataTask(with: etaURL) { [weak self] data, response, error in
// Handle response
}
currentTask?.resume()
}
```
## Contributing
We welcome contributions! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.
## All rights @Shobhakar Tiwari