Lead iOS Engineer

Job Title: Lead iOS Engineer

Location: Ho Chi Minh City, Vietnam

Work Mode: Hybrid (on-site 1–2 days/week or as required)

English Requirement: B2+ (Good communication)

Duration: 12 months (ASAP Start)

Role Overview

We are looking for a skilled and detail-oriented Lead iOS Engineer to develop the native iOS application for Felix AI. This role requires deep experience in Swift and SwiftUI, with strong expertise in real-time audio input/output, WebSocket integration, and mobile performance optimization.

Key Responsibilities

● Lead the end-to-end development of the native iOS app using Swift and SwiftUI following MVVM or TCA architectural patterns.

● Implement real-time audio capture and playback (PCM) using AVAudioEngine, with robust handling of audio interruptions.

● Build and maintain WebSocket client (URLSessionWebSocketTask) for bi-directional, low-latency communication with the backend.

● Integrate REST APIs, Firebase Authentication, and implement offline data caching (Core Data or Realm).

● Optimize app performance (CPU, memory, battery, startup time, UI framerate) using Instruments.

● Achieve and maintain accessibility compliance (WCAG 2.1 AA) with support for VoiceOver, Dynamic Type, etc.

● Write and maintain unit and UI tests (XCTest), target >80% code coverage.

● Own the App Store release process and dependency management via Swift Package Manager (SPM).

● Collaborate closely with backend and DevOps engineers, PM, and UI/UX designer.

Required Qualifications

● 7–10+ years in native iOS development with a strong portfolio of performant apps.

● Expert in Swift and SwiftUI; advanced knowledge of AVFoundation and WebSockets.

● Proven experience handling real-time audio streams, API integration, and optimizing for battery/network.

● Experience implementing offline caching strategies and accessibility compliance.

Preferred Qualifications

● EdTech product experience

● Apple Developer or Swift certification

Key Performance Indicators (KPIs)

● App startup < 2 seconds; sustained 60fps UI

● 80% test coverage; crash-free rate > 99.5%

● Stable real-time audio/WebSocket functionality verified under real-world conditions

● App Store delivery within 3 months of onboarding

● Accessibility compliance (WCAG 2.1 AA) validated through testing