Co-founded Internet Security Research Group (ISRG) in order to build Let's Encrypt, a public benefit certificate authority serving more than 275 million website globally. We've created a strong ecosystem around our certificate issuance and management technology, which focuses on bringing ease of use to a component of the secure Internet stack that has historically been complex and hard to manage. Built the service from the ground up as Executive Director overseeing technical strategy, finances, partnerships, hiring, legal strategy, and compliance.We're now also operating Divvi Up, a privacy-respecting metrics services that we've initially deployed to support COVID-19 Exposure Notification applications run by Public Health Authorities.ISRG's third project, Prossimo, is aimed at bringing memory safety to the Internet's core software infrastructure.

Member of the ISRG Board of Directors.

I work on defining and executing strategies for improving the Web, with a focus on networking, security, and media.

Manager of Mozilla's networking group. Responsible for the security and performance of Mozilla's networking stack, including protocols (e.g. HTTP, SPDY, FTP), SSL/TLS, disk/memory caching, and future networking standards development.

For the first few years my primary responsibility was to modernize Gecko on Mac OS X. Ported subsystems to modern APIs including Cocoa. Improved performance and platform integration.While I maintained Mozilla's Mac OS X port for the duration of my time in this position, I started working primarily on Mozilla's NPAPI plugin (e.g. Flash/Silverlight) support for all platforms in 2008. Improved performance, security, and stability. Led public NPAPI specification efforts.

Most Mozilla Foundation employees transferred to Mozilla Corporation, including me.

Finance committee.

Taught Operating Systems and Computer Architecture with a focus on Linux kernel internals.

Worked in SGI's Linux supercomputing group. Fixed bugs and added features to low-level components of SUSE Linux Enterprise Server and Red Hat Enterprise Linux with a focus on scalability in the kernel and low-level utilities.