Christopher Yim, Developer in Irvine, CA, United States
Christopher is currently unavailable

Christopher Yim

Software Engineer and Developer

Irvine, CA, United States

Toptal member since April 27, 2026

Expertise
C++XcodeObjective-CiOSSwiftGitLLMRAGVirtual RealityWebAssemblyVisual Studio DevelopmentMacOSPythonDatadogC#
Bio

Christopher is a software engineer with nearly 20 years of experience shipping products across gaming, mobile, AR/VR, and AI-powered browsers. He's spent his career jumping into unfamiliar codebases and domains and figuring things out, from pioneering Blizzard's first mobile in-app purchasing to joining the Chromium oncall rotation at The Browser Company without prior Chromium experience. Christopher is at his best when learning something new and delivering.

Portfolio

The Browser Company
C++, Swift, Chromium, Xcode, MacOS, Claude Code, Cursor AI, Codex, Python, Git...
Meta
C++, Unity, Unreal Engine 5, Virtual Reality (VR), Python, WebAssembly (Wasm)...
BLIZZARD ENTERTAINMENT
C++, C#, Unity, iOS, Android, Objective-C, Java, SQL, Mobile Development, Games...

Experience

  • C++ - 20 years
  • Xcode - 15 years
  • iOS - 8 years
  • Games - 7 years
  • Git - 2 years
  • Cursor AI - 2 years
  • Chromium - 1 year
  • Claude Code - 1 year

Preferred Environment

C++, Swift, Objective-C, Unity, Claude Code, Cursor AI, Git, Xcode, Visual Studio Code (VS Code), Chromium

The most amazing...

...project I've worked on was building Blizzard's first mobile in-app purchasing system, which became the pipeline for $700+ million in mobile revenue.

Work Experience

Software Engineer

2024 - 2026
The Browser Company
  • Joined Chromium oncall rotation as the first engineer without prior Chromium experience and led the M145 Chromium upgrade under the security SLA deadline to keep Dia and Arc current with the latest patches.
  • Built an AI personalization pipeline for the Dia browser, optimizing LLM token usage by around 30% by streamlining web content extraction, and developed a continuous scraping manager to keep user memory entries current.
  • Optimized Dia's auto-update system, increasing user adoption of the latest version by over 20% by reducing update friction.
  • Led Xcode 26 migration across Dia and Arc, unblocking the entire engineering team ahead of macOS deprecation and modernizing the UI to support Tahoe Glass.
  • Resolved security vulnerabilities reported through Dia's bug bounty program, including URL spoofing and UI manipulation exploits with CVE classifications.
  • Expanded and stabilized Dia's UI test infrastructure, adding automated regression tests and enabling it as a CI gate on every PR.
Technologies: C++, Swift, Chromium, Xcode, MacOS, Claude Code, Cursor AI, Codex, Python, Git, Sentry, Datadog, Objective-C, AI Prompts, Large Language Models (LLMs), Retrieval-augmented Generation (RAG)

Software Engineer

2022 - 2024
Meta
  • Led the Avatars SDK team, a developer-facing platform used across game studios and Meta products, maintaining team velocity through organizational transitions.
  • Built QA automation and visual regression tooling in Unity that reduced the SDK release cycle by 2 weeks.
  • Migrated SDK to auto-generated IDL-based bindings across C#, WebAssembly, and other targets, replacing error-prone manual bindings with a single source of truth.
  • Demonstrated the feasibility of rendering Meta Avatars in the browser using WebAssembly, leading to the adoption of the work by another team to continue development.
  • Expanded Avatars SDK to support Unreal Engine, enabling a new third-party partner integration.
Technologies: C++, Unity, Unreal Engine 5, Virtual Reality (VR), Python, WebAssembly (Wasm), C#, Android, CI/CD Pipelines, SDK Development, IDL

Senior Software Engineer

2008 - 2021
BLIZZARD ENTERTAINMENT
  • Architected the back-end for Hearthstone's Mercenaries game mode, launched to 20+ million active players, owning data modeling, progression, matchmaking, monetization, and designer-facing tooling.
  • Owned server-side monetization systems powering hundreds of millions in annual revenue, and built virtual currency support for China to comply with new regional regulations.
  • Integrated Battle.net's revamped storefront and catalog system, enabling in-game sales, promotions, and free item distribution for Hearthstone, being the first team to do so.
  • Shipped legendary duplicate protection for card pack openings under a tight expansion deadline.
  • Built Blizzard's first mobile login and in-app purchasing system across iOS, Android, and Amazon Appstore, establishing the pipeline for what became a $700+ million mobile revenue channel.
  • Championed centralizing mobile infrastructure across game teams through Blizzard's tech council, leading to a shared mobile login and push notification SDK adopted company-wide.
  • Designed and built a headless account system with the Battle.net team to reduce new player friction, increasing throughput past tutorial by 75%.
  • Built a Refer a Friend feature, increasing new player accounts by 10%.
  • Built Blizzard's first mobile applications, including the authenticator (two-factor auth), WoW Mobile Armory, and BlizzCon companion app.
  • Shipped Auction House and Guild Chat for Mobile Armory, enabling first-ever mobile interaction with WoW game servers.
Technologies: C++, C#, Unity, iOS, Android, Objective-C, Java, SQL, Mobile Development, Games, In-app Purchase (IAP), CI/CD Pipelines, Xcode

Experience

Hearthstone Mercenaries

https://hearthstone.blizzard.com/en-us/mercenaries
Architected the back-end for Hearthstone's Mercenaries game mode, a collect-and-battle RPG launched to Hearthstone's 20+ million active player base. I built on top of Hearthstone's existing server infrastructure, and the system handled data modeling for progression, matchmaking, loot tables, monetization, and designer-facing tooling.

The hardest part was building systems flexible enough for designers to iterate on the game while it was still taking shape, while also integrating monetization from the start and keeping it all stable for millions of players. Mercenaries shipped in October 2021 and ran as a live service game mode.

Skills

Tools

Xcode, Claude Code, Git, Codex, Sentry, AI Prompts

Languages

C++, Swift, Objective-C, Python, C#, IDL, Java, SQL

Paradigms

Mobile Development

Frameworks

Unity

Platforms

Visual Studio Code (VS Code), MacOS, Android, iOS

Storage

Datadog

Other

Games, Cursor AI, Chromium, Large Language Models (LLMs), Retrieval-augmented Generation (RAG), Unreal Engine 5, Virtual Reality (VR), WebAssembly (Wasm), CI/CD Pipelines, SDK Development, In-app Purchase (IAP)

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