iOS Engineer (Swift and Objective-C)
Status: Open
- Pay
- $110/hr
- Location
- Remote — Germany, India, Thailand, The United States, Timor Leste, Vietnam
- Employment type
- Contractor
About this opportunity
Required skills
- Performance Optimization
- Concurrency (GCD/async-await)
- Objective-C
- UIKit/SwiftUI
- iOS
- Code review
- Debugging
- Memory Management (ARC)
- SWIFT
- Networking
What you'll do
- Develop AI Training Content: Create detailed prompts across iOS topics and write high-quality reference answers to guide AI learning.
- Optimize AI Performance: Evaluate and rank AI responses to enhance correctness, security, performance, and maintainability.
- Ensure Model Integrity: Test AI outputs for inaccuracies or unsafe recommendations, validating reliability across real-world iOS use cases.
Requirements
- Bachelor’s degree or higher in Computer Science, Software Engineering, or a closely related technical field (or equivalent practical experience).
- 4+ years of professional experience building production iOS applications, including work in Swift and (ideally) Objective-C codebases.
- Expert-level proficiency in Swift (Swift 5+): value/reference semantics, generics, protocols, error handling, and modern language features.
- Strong iOS fundamentals: app lifecycle, view/controller architecture, navigation, state management, and background execution constraints.
- Solid concurrency experience: GCD, OperationQueue, and modern async/await patterns; ability to reason about race conditions and thread-safety.
- Strong understanding of ARC and iOS memory patterns (retain cycles, weak/unowned, leaks, Instruments).
- Experience with networking and data: URLSession, JSON parsing, caching, retries, offline strategies, and persistence (Core Data/SQLite/Realm).
- Experience with testing and quality: XCTest, UI testing, mocking strategies, CI/CD (Fastlane is a plus), and App Store release hygiene.
- Security awareness: secure storage (Keychain), transport security, auth flows, privacy permissions, and sensitive data handling.
- Minimum C1 English proficiency (written and spoken), with the ability to write clear technical explanations and follow detailed English-language guidelines.
- Previous experience with AI data training, annotation, or evaluating AI-generated technical content is a strong plus.
- Highly detail-oriented and systematic, with a methodical approach to evaluating reasoning quality and identifying subtle issues in complex iOS code.