• Owned urgent customer escalations involving Xen compatibility and OCI image failures:
  • Diagnosed a "Bad page state in xenwatch" kernel BUG causing CreateContainerError on PV guests with mounts -- root-caused to a xenstored regression, fixed via revert in Edera's Xen fork, discovered independently while building a repro environment ahead of directed team troubleshooting.
  • Diagnosed silent OCI image assembly failures stalling large workload launches -- root-caused to fundamental correctness gaps in the existing implementation, resolved by prototyping and integrating ocirender as a ground-up replacement over a single weekend.
• Designed and implemented ocirender, a streaming OCI image layer merge engine in Rust that converts container images directly to squashfs, tar, or directory output without intermediate disk extraction -- eliminating a class of OCI image correctness bugs (including silent hard-link truncation from PAX header mishandling), reducing disk space requirements, improving conversion throughput via download-parallel streaming, and replacing ad-hoc "can we run a Docker image" testing with a comprehensive suite of synthetic merge tests and production-derived regression cases.
• Implemented vPCI-based PCI passthrough under Xen PVH for NVIDIA GPUs in Edera's Xen fork, built on an experimental AMD prototype that had only been validated with NICs:
  • Fixed vPCI BAR address handling, IOMMU memory access permissions, and MSI-X interrupt remapping (including a security check ensuring interrupt remapping is active before MSI-X setup) to enable correct GPU operation under PVH.
  • Added SR-IOV VF support under vPCI, fixed ReBAR capability handling, and resolved CPUID topology (leaves 0x80000008 and 0xB) and TSC reliability issues surfaced during bring-up.
  • Wrote CUDA-based VRAM scrubbing to clear GPU memory between guest transitions, eliminating residual data exposure across zone launches.
• Designed and implemented automatic vNUMA configuration for Xen PVH guests in Edera's Rust-based toolstack, requiring no customer topology configuration:
  • Placement algorithm selects NUMA nodes based on PCI device locality (via XEN_SYSCTL_pcitopoinfo), expanding across nodes by minimum SLIT distance to cover vCPU count without oversubscription, with guest memory split proportionally to free memory across selected nodes.
  • Generates ACPI SRAT/SLIT tables and hard-binds vCPUs to physical CPUs to ensure guest kernel topology discovery matches physical placement.
  • Required companion fixes in Edera's Xen fork: correcting CPUID leaves 0x80000008 and 0xB to match vNUMA topology, preventing LLVM OpenMP's CPUID-based socket detection from misidentifying NUMA boundaries and misallocating threads.
• Introduced Tracy profiler instrumentation across Edera Protect daemons to diagnose pod creation latency concerns raised by a prospective customer (measured via ClusterLoader2):
  • Identified and fixed the primary latency sources, resolved via the CRI and networking fixes mentioned below.
  • Identified a remaining structural bottleneck: PVH dom0 maps guest pages one-by-one during domU bringup (kernel/initrd copy), generating significant hypercall overhead and TLB shootdowns -- in contrast to PV dom0 which can batch-map guest pages. Cross-domain mmap batching for PVH dom0 is not currently implemented in Xen upstream.
• Diagnosed and fixed a cluster of latent CRI correctness and latency bugs in Edera Protect's Kubernetes integration:
  • Fixed a race between StartContainer and ContainerStatus reporting a zero startedAt timestamp while in Running state, causing tools like ClusterLoader2 to report nonsensical Perc99 pod startup latencies.
  • Fixed pod destruction latency by correctly distributing resource teardown across StopPodSandbox and RemovePodSandbox per Kubelet's expectations.
  • Fixed a post-fork lock-safety bug in network namespace creation that caused intermittent PID leaks.
• Eliminated first-packet latency in Edera Protect's direct zone networking by replacing per-destination ARP resolution with a static phony gateway and injected ARP table entry -- caused by the ARP proxy treating every destination IP as link-local.
• Designed and deployed a nightly benchmark pipeline for tracking Edera Protect performance regressions across CPU, memory, disk, and Linux kernel API workloads:
  • Modified Phoronix Test Suite with reduced duration and fewer variants, but 11–17 samples per run, enabling statistically meaningful box-and-whisker distributions across percentiles and variance.
  • Fedora lab hosts managed via snapper snapshots for clean per-run isolation and frictionless developer checkout/rollback between nightly runs and ad-hoc development work.
  • Results stored in ClickHouse and visualized in Grafana, deployed via Helm to GKE -- with a longer-term goal of dogfooding Edera Protect as the runtime for the dashboarding infrastructure itself.
• Built edera-debug-report, a customer-facing diagnostic tool (Python, intentionally chosen for auditability) that collects hardware, firmware, kernel, and Edera Protect configuration data into a local ZIP archive -- with no network transmission, granular privacy opt-outs, and explicit review guidance -- to accelerate diagnosis of hypervisor, hardware, and software compatibility failures in enterprise deployments.

Independently developed the "10000th Anniversary Edition" remaster of Darwinia, rewriting the majority of the 2005-era engine for performance and compatibility on modern hardware. Introversion Software adopted the work and has shipped it on Steam and GOG for macOS, Windows, and Linux.

• Redesigned and rewrote the graphics subsystem from scratch, replacing the original fixed-function OpenGL pipeline (no vertex buffers, framebuffer objects, vertex arrays, or shaders) with OpenGL 3.3 core and OpenGL ES 3.0. Uses ANGLE to support Vulkan, Direct3D, Metal, and OpenGL backends. Introduced MSAA/SSAA/SMAA/FXAA anti-aliasing and AMD FSR 1.0 upscaling.
• Achieved dramatic performance improvements through a combination of instanced rendering, vertex buffer adoption, vector math rewrites, and aggressive profiling with Tracy — particularly on geometry-heavy maps where the original engine's fixed-function pipeline was a severe bottleneck on modern hardware.
• Rewrote the sound engine using MiniAudio, adding multithreaded spatialized audio and up to 7.1-channel surround sound. The original engine only supported DirectSound spatialization on Windows with stereo output.
• Rewrote the custom UI toolkit with dynamic DPI scaling for high-DPI display support.
• Improved platform portability: 64-bit CPU architecture support, native Apple Silicon, and rendering optimizations for tile-based GPU architectures.
• Fixed numerous long-standing bugs across entity AI, game logic, math, sound, and input handling — some resolved as a side effect of engine modernization, others requiring direct debugging. This represents six years of ongoing maintenance and refinement.
• Worked directly with GPU driver teams at AMD, NVIDIA, Intel, and Qualcomm to diagnose and resolve driver bugs, several of which were fixed in upstream driver releases.
• Made multiple upstream contributions to ANGLE, MiniAudio, and SDL arising from issues encountered during development (see Open Source Contributions). Developed gloam, a high-performance API loader generator, to address size and performance limitations of existing loaders used in the engine.
• Maintains all open source dependencies as patched forks under the IntroversionSoftware GitHub organization, enabling rapid integration of fixes and full audit trail of all modifications.

• Developed Valve Anti-Cheat and Steam Trust machine learning model and infrastructure. Implemented several new detection methods and heuristics for cheat and bot detection. These methods resulted in much higher and more accurate detections, improving the game experience for millions of daily users.
• Low-level x86 Steam Datagram Relay (SDR) and game server I/O performance tuning and accompanying tooling, allowing for much more efficient use of hardware and consistent low-latency experience for users.
• Cross-platform (Windows/Linux/macOS) software and game porting/development
• Anti-fraud and anti-bot infrastructure to combat automated account creation, cheating, and other malicious activity. Worked with Google to improve reCAPTCHA and other anti-fraud tooling for Valve's use case.
• Several improvements to the Steam Hardware Survey, improving data sanitization and gathering
• Game Networking Sockets library development, maintenance and porting. The library provides developers with a good basis for multiplayer game networking, with support for the Steam Datagram Relay (SDR) infrastructure.
• Steam Deck OS and Proton development and low-level x86 tuning/debugging, mostly on the Wine and kernel side. Improved compatibility and performance for many games across the board.

• Built a scalable, multi‑cloud test‑automation framework -- covering AWS, Azure, and on‑prem OpenStack -- to qualify base OS images, new hardware platforms, and virtualization environments
• Defined and implemented platform‑qualification tests (NUMA topology, vCPU‑to‑pCPU pinning, CPUID reporting, memory‑bandwidth, CPU throughput, I/O latency) to surface misconfigurations before production rollout
• Delivered a unified VM image builder that automatically generates hardened Linux images for all target clouds -- reducing manual setup and drift across environments
• Engineered a Linux VM–image security‑hardening toolchain (configuration audit, patch management, CIS benchmark enforcement) to ensure compliance with corporate and regulatory standards

• Improved stability and performance of customer-facing Terraform modules and infrastructure.
• Developed new end-to-end testing infrastructure, with greater visibility and insight into: long-tail runs, distinct failure modes, cloud service provider reliability, product reliability, etc.
• Designed and implemented new product release qualification procedures and requirements, focusing on customer experience, minimizing customer frustration.
• Implemented new TCMS infrastructure using Qase (migrating from TestRail) for cost-saving and reliability reasons.

• Developing Vulkan graphics drivers for the AMD-based GPU in Samsung phones.
• Solved multiple conformance issues with Vulkan dEQP on the Samsung User Mode Driver (SUMD).
• Implemented new features to better support ANGLE and improve rendering performance.

Linux kernel engineer, software engineer, and performance guru.

• Development focus on several key areas while with Amazon EC2: block I/O performance, network throughput/latency, hypervisor scheduling and resource allocation, scalable fleet validation and testing infrastructure, and new platform development.

• Primary platform team engineer responsible for multiple platforms:

  • High-capacity HDD-based High Storage (HS1) platform (hs1.8xlarge). Aside from base platform development, implemented generally applicable core platform tooling for resource affinity to ensure high throughput.
  • First SSD-based High I/O (HI1) platform (hi1.4xlarge). Aside from base platform development, implemented several kernel, hypervisor, and userspace changes to ensure high I/O per second (IOPS) rate.

• Developed critical tooling for platform performance and development:

  • Wrote declarative tools/services for fair resource management on all EC2 instance types (PID affinity, IRQ affinity, vCPU/pCPU pinning, CPUID topology).
  • Co-author of a fast, scalable, and reliable tool infrastructure (internally called "Mjollnir") used for platform qualification, benchmarking, testing, and emergent operational use cases. To this day, Mjollnir still enables engineers to rapidly prototype and qualify platforms for the Amazon EC2 fleet.

• Developed the Linux port of Defcon, using C++, SDL, SDL_image, SDL_mixer and OpenGL.
• Assisted in the development of the Windows Vista version of Darwinia, which was released on MSN Games shortly after Windows Vista's release.

• Developed the Linux and macOS ports of Hacker Evolution: Untold. Was tasked with eliminating the use of DirectX and Windows-specific APIs, and refactored the code to use much more cross-platform APIs including SDL, SDL_image, SDL_mixer, and OpenGL. The project is written in pure C++.

• Achieved rank of Eagle Scout in 2001.
• Vigil Honor in Order of the Arrow.
• Was active in cub scouts, achieved all ranks (Bobcat, Wolf, Bear, Webelos).