Senior iOS Engineer

We are seeking a Senior iOS Engineer to join a greenfield SDK development initiative for one of the world’s largest contextual advertising platforms. This is a foundational engineering role, not a maintenance gig. You will build a production-grade Prebid Plugin Renderer SDK from scratch on iOS, enabling the client to monetize premium non-gaming mobile inventory through Banner, MREC, and VAST video ad experiences.

The role demands deep native iOS expertise, hands-on experience integrating with mobile ad ecosystems (ideally Prebid), and the discipline to ship clean, testable SDK code. You will own the iOS track end-to-end, from architecture through delivery, working closely with your Android counterpart, a QA automation engineer, and a part-time TPM.

About the Project

The client is a global leader in contextual advertising with a dominant desktop and web presence. The challenge: Client currently lacks a proprietary mobile ad SDK, leaving significant premium mobile inventory at risk of monetization.

Key Responsibilities

iOS SDK Architecture & Engineering

• Design and implement the full iOS Prebid Plugin Renderer SDK from scratch
• Build the PrebidMobilePluginRenderer interface integration with Prebid Mobile SDK v3.2.0+
• Architect layered SDK structure: foundation, display rendering, video rendering, tracking, telemetry
• Establish iOS project structure, build system (CocoaPods / Swift Package Manager), and SDK distribution pipeline
• Make platform-specific technical decisions and ensure alignment with iOS SDK best practices

Display Rendering

• Implement WKWebView-based HTML creative rendering for Banner and MREC ad placements
• Build adaptive sizing logic for standard IAB formats (320×50, 300×50, 300×250)
• Implement MRAID 3.0 bridge: expand, resize, and close command handling
• Handle click interception, landing page routing, and in-app browser coordination

Video Rendering (VAST in Banner/MREC)

• Integrate native video player (AVPlayer) with full VAST XML parsing and wrapper chain resolution
• Implement video player lifecycle management — play, pause, mute, visibility-aware pause/resume on scroll
• Build VAST quartile tracking (start, 25%, 50%, 75%, 100%) and video OTA control application
• Integrate OMID video viewability measurement and support IAB certification requirements

Tracking, Privacy & Measurement

• Implement burl/nurl impression tracking with configurable viewability threshold (50% visible for 1s)
• Build click tracking with pre-browser-open pixel fire sequencing
• Integrate TCF v2.0 (GDPR) and GPP (US Privacy) consent string parsing and macro replacement
• Wire PluginEventListener callbacks to Prebid SDK for impression, click, and lifecycle events
• Implement retry logic and local event queuing for network failure resilience

OTA Configuration & Telemetry

• Build OTA Config System: backend API handshake, local cache (24h TTL), fallback to hardcoded defaults
• Apply Phase 1 OTA parameters across display and video rendering paths
• Implement telemetry system: SDK init heartbeat, structured error capture, performance metrics upload

Quality & Collaboration

• Write thorough unit tests using XCTest + XCUITest with external dependencies mocked via XCTest mocks
• Maintain code coverage above team-defined threshold; coverage drops block PR merges
• Validate Prebid SDK integration, OMID session lifecycle, and backend API failure scenarios
• Collaborate with the QA automation engineer to ensure CI/CD pipeline integrity and device matrix coverage

Required Qualifications

• 5+ years of professional native iOS engineering experience (Swift)
• Strong track record building and shipping production iOS SDKs or complex libraries (not just apps)
• Demonstrated experience integrating with mobile advertising ecosystems — Prebid Mobile SDK experience is MANDATORY
• Hands-on experience with mobile ad formats: Banner, MREC, VAST video, MRAID
• English level: Upper-Intermediate (B2) or higher — regular stakeholder and cross-team communication required

Technical Acumen

• Expert-level Swift and iOS SDK/framework knowledge
• Deep understanding of UIKit/SwiftUI, app lifecycle, Grand Central Dispatch, and ARC memory management
• Native video player expertise — AVPlayer integration, VAST XML parsing, and playback lifecycle management
• WKWebView / web content rendering — HTML creative display, JavaScript bridging, MRAID command handling
• Mobile ad tracking implementation — impression/click pixels, BURL/NURL, viewability measurement
• OMID / OM SDK integration experience (display and/or video)
• Privacy framework knowledge — TCF v2.0, GPP, consent string parsing and propagation
• Proficiency with CocoaPods / Swift Package Manager for dependency management and SDK distribution
• CI/CD experience — GitHub Actions, automated testing pipelines, XCUITest in CI
• Profiling and debugging with Instruments (Xcode) — memory leaks, CPU hotspots, network inspection

Domain Knowledge

Adtech domain experience is not optional for this role. Candidates must understand the Prebid Mobile SDK architecture and plugin renderer interface. Knowledge of OpenRTB bid response structure, ad serving fundamentals, and IAB measurement standards (OMID, MRC viewability) is expected.