As Snap grew from pre-IPO startup to 750MM MAU / $4.6B revenue, I had 3 core responsibilities.As chief software architect, I reported to the COO / SVP of Eng (Jerry Hunter) and owned tech direction for a growing scope of 450 engineers at first to a peak of 2350. Snapchat is a complex “12 mobile apps in 1”, with thousands of back-end servers running across AWS, GCP and on-prem. Each feature wants all the resources of a phone to create the most compelling experience. This means orchestrating concurrent and battery efficient use of network, CPU, GPU, APU, video codecs and camera – much like an OS. Components need clean isolation to avoid corruption or hogging by background features while maximizing the customer’s experience for whatever they are engaging at the moment.API design was not enough to achieve this, so I also led technical ops. The hardest aspect was building our Customer Experience Program (CEPP) that ensured features and platform components achieved performance, battery and metrics accuracy goals. This scaled from app startup latency and messaging reliability to 50 areas and 500 customer-focused “end to end” metrics. I built cross-functional collaborations across eng, design, monetization and finance in several ops programs including CEPP, where we reported and reviewed metrics in weekly leadership forums. I used these to ensure API and service shortfalls were being continuously identified and renovated to meet the demands of new features, growing scale and cost.Last, I owned key aspects of Eng culture: designing and (co-)authoring the Eng ladder system, roles \ leveling \ hiring guidelines, OKR framework, and perf \ calibration \ promo process. I built the Eng promo and hiring budget analysis with HR, to ensure a healthy balance of level distributions. I mentored 100 of the senior-most engineers each quarter, and created dedicated challenges to grow top talent into bigger roles.

Founded and managed Activision Seattle studio - an advanced development team which helps title studios explore disruptive technologies and stay ahead of industry trends. The team performs R & D and builds API and tools in graphics, online services (e.g., matchmaking) and asset pipeline tooling. Inter-studio integration and simplification is a key theme.Activision takes a hand's on approach to engineering delivery, so a sizable chunk of time was end-to-end ownership of engineering design, project management, docs/patents, tech integration (code, tools, services), and operations...whatever it took to deliver the games on-time.My studio worked on all versions of Call of Duty (Advanced Warfare, Black Ops3, Infinite Warfare, Online China), Destiny and some Skylanders (both mobile and console).Credited titles:2014 Destiny, Call of Duty: Advanced Warfare2015 Destiny The Taken King2016 Skylanders Battlecast

I identified big industry opportunities (e.g., capturing enterprise customers with high performance computing and storage solutions), and then built products across sometimes large organizational separations within AWS. This meant quickly learning "enough" about widely different engineering fields, and then filling gaps between teams until the product was built, shipped and operating smoothly. A great deal of new invention happened with this work - issued patents span a dozen tech disciplines.* chief engineer (and part-time biz) owner for High Performance Computing (HPC) products in EC2, including Cluster Compute 1 & 2, Cluster GPU, High IOPS, High/Dense Storage, High Memory Cluster* Commodity computing optimization - improved fleet occupancy, cheaper high radix networking, etc.* end to end engineering for new hardware in EC2 across networking, virtualization (e.g., GPUs, next-gen CPUs) rack/server design, fleet management, software service architecture* Amazon-unique hardware designs* design architect for infrastructure tools including high scale fleet-integrated test services, anti-entropy fleet deployment, distributed load testing and health monitoring* built and managed Platforms, Performance and Tools (PPT) Team - mostly Principal Engineers responsible for cross-divisional initiatives in tools infrastructures, performance analysis and optimization, operating systems, virtual machine management, and security* hardware and software vendor engagements, high-scale enterprise customers

Software, firmware and hardware security design and analysis for next generation hardware and console emulation: Project 434. ...later part of XBox One platform for emulating Xbox 360 games.

* built and managed 5 project teams (30 engineers) in many-core computing (e.g., light-weight concurrency), OS and grid security, zero day worm protection* Craig Mundie's (CTO) Redmond advanced development group at the time* personally authored extreme performance numerics libraries for crypto in C++ and x64 ASM

* Inventor and lead engineer for DRM isolation and anti-tampering used in Office RMS, eReader, parts of Media Player and Windows Licensing* manager and architect on Red-Green Desktop, a multiple virtual machine integrated desktop product for Hyper-V* systems software development for desktop and mobile: hypervisors, run-time code generation, secure boot, Trusted Platform Modules (TPM)* C, C++, x86/x64 and ARM ASM* numerous innovations in security, anti-reverse engineering, binary obfuscation, anti-debugging, intrusion detection* expertise in threat model analysis (TMA), secure key storage, DRM licensing, mobile and console device security* designer and lead developer of rights management activation service architecture, activation and licensing web servers, cryptography libraries

Designed and implemented Windows SDK in C++, x86/x64 ASM for sophisticated image filtering, numerical solvers using interval arithmetic and automatic differentiation, collision detection, computational geometry primitives; shipped with GDI+, DxUtils/D3DX (DirectX 5, 6 and 7)

Designed and implemented Windows API in C/C++ for:* highly efficient processing of 2D content for 3D game environment, including image and palette caching, on-the-fly color model mapping on blts, RLE compression, 2D sprite and animation engine* collision detection for 3D rendering engine* shipped with V-Chat and V-Worlds products as part of MSN

C/C++, FORTRAN, SPARC ASM software development at various companies, UNIX (BSD, SunOS, System V)1994, 1993 AT&T, Bell Labs – 3D animation and computational geometry, Korn shell plug-ins1992 RCA, David Sarnoff Research Center – image processing and machine vision1991 Statistical Graphics Corp – demos and statistics plug-ins1990, 1989 Princeton Plasma Physics Lab – data analysis and tools1988 GE, Astrospace Division – data entry for experiment mass/moment of inertia on Mars Observer (the one that crashed, hopefully not my fault)