Ladd Van Tol

September 2022 - February 2024

Worked on Amazon's flagship iOS shopping app, primarily focused on performance, resilience & observability.

• Tackled performance challenges with Amazon's server-driven UI stack
• Evaluated, procured, and integrated third party crash reporting, with on-premise backend deployment
• Shipped a Swift rewrite of the network stack
• Advocated for improvements to a fragmented multi-repo/multi-pipeline developer federation model
• Prototyped and demoed distributed tracing, utilizing OpenTelemetry and AWS X-Ray
• Ported internal developer tooling to ARM64 architecture, halving local build times

December 2010 - July 2022

Wrote eBay's first native mobile app for iOS, and helped build the developer community and ecosystem supporting ongoing development of high quality mobile apps at eBay.

• Technical lead for eBay's iOS app, launching as one of the first 500 apps in the App Store (2008)
• Native mobile architecture lead, providing architectural and implementation underpinnings for the eBay iOS native app
• Technical coordination between iOS, Android, web front end and service teams
• Standard-setting for web service/app interface layer, utilizing OpenAPI, GraphQL and other solutions
• Extensive collaboration with security and identity teams, including defining and building an effective bot blocking solution for eBay's API stack
• Performance optimization of native app implementations, and network stack
• Native app telemetry, leveraging both custom solutions and OpenTelemetry
• Significant ongoing work on resilience and reliability
• Supported velocity, developer productivity, and devops initiatives. Efforts here included transitioning to trunk-based development with weekly releases. Technical efforts included patching performance bugs in the Swift compiler, and helping teams with Xcode performance holes.

(continuing work started at Critical Path Software in 2008, acquired by eBay, Inc. in December 2010)

August 2004 - December 2010

Consultant, providing engineering services for a variety of well-known companies. Projects include:

• eBay app for iOS
• Internet video-on-demand for Mac and Windows
• Blog-related web application, running as a Java servlet on Linux
• Halftoning implementation for a printer driver
• Game emulation system for Mac
• Port of a major browser plugin to Mac Intel systems
• Instant Messaging client on Mac
• Online poker client for Mac
• Qt-based GUI application for Linux

March 1996 - Present

September 1998 - July 2004

Handled a variety of major projects, including:

• Lead Engineer for VersionTracker Pro product line on Macintosh and Windows.
• Designed two iterations of database schema powering VersionTracker site.
• Substantially expanded VersionTracker site, designing technical aspects of many key features, including user ratings and reviews.
• Developed web spidering technology essential to the business.

June 1998 - August 1999

• At the University of Wisconsin, researched ray tracing software for the Visible Human Dataset
• At CalTech, researched land mine locating robots, using novel plume-tracking techniques

September 1997 - December 1999, September 2002 - May 2003

August 1996 - May 1997