Staff Software Engineer - iOS

🎯 Executive Summary

iOS veteran with 10+ years building apps that reach 4+ Billions users globally. Proven track record leading large-scale technical initiatives, managing cross-functional teams, and delivering measurable business impact through code excellence.

Key Achievements:

• 🏆 Technical Excellence Award winner at Snap Inc. (company-wide recognition)
• 📊 Top 20 all-time committer to Snapchat iOS codebase (out of 1000+ iOS engineers)
• ⚡ 60% latency reduction in Snapchat video playback (4B monthly views)
• 🏗️ 200K+ lines architecture refactor lead (Matcha project, 10 engineers, 30+ teams)
• 👥 100M daily users served by features under my ownership
• 📈 Staff Engineer at Meta - highest IC level achieved

Core Competencies:

• ✅ iOS Architecture & System Design (massive scale)
• ✅ Team Leadership & Cross-functional Collaboration
• ✅ Performance Optimization & Metrics-Driven Development
• ✅ Large-scale Refactoring & Technical Debt Management
• ✅ Product Thinking & User-Centric Engineering

💻 Technical Skills

Languages & Paradigms

• Expert: Swift, Objective-C
• Proficient: TypeScript, Python, Shell scripting
• Paradigms: OOP, Protocol-Oriented Programming, Functional Programming, Reactive Programming

iOS Frameworks & Technologies

• Core: UIKit, SwiftUI, Combine, async/await, Core Data, Core Animation
• Media: AVFoundation, Core Audio, Photos, Camera, Core Image
• System: GCD, NSOperationQueue, Core Bluetooth, Core Location, Push Notifications
• Advanced: Metal, Core ML, ARKit, HealthKit, App Extensions

Tools & Platforms

• Development: Xcode, VSCode, Git/GitHub, CI/CD pipelines
• Debugging: Instruments, LLDB, Charles Proxy, Network Link Conditioner
• Analytics: A/B testing frameworks, SQL, Custom metrics dashboards
• Collaboration: JIRA, Slack, Phabricator, Code review systems

Architecture & Patterns

• Design Patterns: MVC, MVVM, Coordinator, Dependency Injection, Repository
• Architecture: Modular architecture, Feature frameworks, Clean Architecture
• Best Practices: SOLID principles, Protocol-oriented design, Memory management

💼 Professional Experience

Meta (Facebook) | June 2025 - Present

Staff iOS Engineer - Facebook & Instagram

Facebook iOS, Instagram iOS (4+ Billion MAU)

Focus Areas: Feed Ads, AI-Enhanced Development Efficiency, Cross-platform Engineering

Impact:

• Building features that serve 3+ billion monthly active users
• Driving iOS development efficiency through AI tooling integration
• Contributing to Feed Ads monetization infrastructure
• Collaborating across iOS, Android, and Web platforms

Snap Inc. | March 2019 - June 2025

iOS Tech Lead - Snapchat

Snapchat iOS (400M DAU, 800M MAU)

Leadership & Impact:

• 👥 Led iOS team for Memories, serving 100M daily users
• 📊 Owned core metrics for playback latency (4B monthly views)
• 🏆 Awarded Technical Excellence Award (company-wide recognition)
• 🎖️ Promoted to company-level Matcha architecture lead (Memories + ECommerce teams)

Technical Achievements:

Performance Optimization:

• ⚡ 60% reduction in P90 video viewing latency
• ⚡ 40% reduction in P90 image viewing latency
• 📈 Measurably boosted downstream engagement through prefetching improvements
• 🔬 Investigated A/B test regressions to maintain technical excellence

Architecture & Leadership:

• 🏗️ Led Matcha project: 200K+ lines refactored for modern architecture
  • Managed 10 engineers across multi-quarter initiative
  • Coordinated with 30+ teams across the company
  • Designed architecture split into 100+ modular libraries
  • Implemented proper dependency injection patterns
  • Wrote substantial portions of production code personally

Feature Development:

• 📝 Built comprehensive story editor from scratch (10M+ daily users)
  • Create, edit, and order snaps within custom stories
  • Full multimedia editing capabilities
• 🔄 Refactored 10K+ lines to use latest platform frameworks
• ✨ Significantly improved user experience through code modernization

Hardware Integration:

• 🚁 Launched Pixy (Snapchat flying drone camera)
  • Owned pairing, transfer, and preview flows
• 📷 Major contributor to Spectacles V3 launch (dual cameras)
  • Rewrote entire data transfer stack (BLE, Bluetooth Classic, WiFi)
  • Designed for expandability across future hardware devices

Manufacturing & Quality:

• 🏭 Managed factory app code & release pipelines
• 🌏 Deployed to QC processes in China and Taiwan factories

BMW Technology Corporation | May 2017 - March 2019

Senior iOS Engineer - BMWConnected & MINIConnected Apps

Connected Car Platform:

• 🗺️ Owned POI search and trip management features
• 🌍 Map framework management: Built abstraction layer for multiple providers
  • HERE Maps (USA), Apple Maps (Japan)
  • Custom bundling scripts for regional App Store builds
• 🌐 i18n maintenance: Python scripts for translation automation

Cross-Platform Innovation:

• 🚙 Built first-generation in-car head units (Node.js/TypeScript)
• ⚛️ Developed React Native after-sales features (iOS + Android code sharing)
• 📡 Implemented push notification infrastructure (RabbitMQ messaging)

AI & Personalization:

• 🤖 Collaborated with ML team on data collection
• 📍 Enabled personalized promotions and learned destinations (home, work)
• 🔬 Prototyped new frameworks to enhance user experience

Citigroup | April 2016 - May 2017

Senior iOS Engineer - Citi Mobile

App: Citi Mobile on iTunes

Banking Features:

• 💳 Owned codebase for cards, bill payments, and account management
• 📅 Built calendar integration with import/export and reminders
• ⌚ Apple Watch support for account summaries
• 📊 Integrated credit score reports into the app

Innovation:

• 🗣️ Prototyped Pay-with-Siri features (cutting-edge at the time)
• 🔬 Proposed new frameworks to enhance user experience
• 💰 Millions of users managing their finances daily

🎓 Education

Master of Science in Electrical Engineering
University of Colorado Denver | Denver, CO

Bachelor of Engineering in Electronics Engineering
Beijing Technology and Business University | Beijing, China

🌟 Why Work With Me?

Technical Excellence

I don’t just write code – I architect systems that scale. From managing 4 billion monthly video views to refactoring 200K+ lines of production code, I’ve proven I can handle complexity at any scale.

Leadership That Delivers

Leading 10-person teams across 30+ partner teams taught me that great code alone isn’t enough. Communication, planning, and bringing people together around a shared vision – that’s where impact happens.

Impact-Driven Mindset

Every line of code should solve a real problem. Whether it’s cutting latency by 60% or building features for 100M daily users, I focus on measurable outcomes that matter to users and business.

Continuous Learning

Tech moves fast. I stay ahead by constantly learning – evident from this blog with 41K+ words written this month alone on AI, fusion energy, market analysis, and more. I bring that curiosity to every project.

📄 Download Resume

Interested in working together?

📥 Download Full Resume (DOCX)

Or reach out directly:

📧 Email: sheldon.wang7@yahoo.com
📱 Phone: 720.772.9666
💼 LinkedIn: linkedin.com/in/sheldonengineering

Last Updated: October 2025