Posts on Warfield Notes

S3 Files and the Changing Face of S3

Tue, 07 Apr 2026 00:00:00 +0000

Part 1: The Changing Face of S3

First, some botany

It turns out that sunflowers are a lot more promiscuous than humans.

About a decade ago, just before joining Amazon, I had wrapped up my second startup and was back teaching at UBC. I wanted to explore something that I didn’t have a lot of research experience with and decided to learn about genomics, and in particular the intersection of computer systems and how biologists perform genomics research. I wound up spending time with Loren Rieseberg, a botany professor at UBC who studies sunflower DNA–analyzing genomes to understand how plants develop traits that let them thrive in challenging environments like drought or salty soils.

A Little Bit Uncomfortable

Tue, 16 Dec 2025 00:00:00 +0000

I can make you scared, it’s kind of what I do If you’re prepared, here’s what I propose to do.

– “Scared”, The Tragically Hip

I am reasonably scared of public speaking.

It used to be a lot worse – I used to be terrified of it. When I was a master’s student, just starting to do computer science research, I went to a small workshop in Bertinoro, Italy to present a paper that I’d written. It was my first time presenting my own work in front of an audience that wasn’t a classroom of other students, and I went back to my room and vomited every single day after lunch from Monday to Thursday. I threw up from the anxiety of imagining how badly it might go.

In S3 Simplicity Is Table Stakes

Fri, 14 Mar 2025 00:00:00 +0000

On March 14, 2006, NASA’s Mars Reconnaissance Orbiter successfully entered Martian orbit after a seven-month journey from Earth, the Linux kernel 2.6.16 was released, I was getting ready for a job interview, and S3 launched as the first public AWS service.

It’s funny to reflect on a moment in time as a way of stepping back and thinking about how things have changed: The job interview was at the University of Toronto, one of about ten University interviews that I was travelling to as I finished my PhD and set out to be a professor. I’d spent the previous four years living in Cambridge, UK, working on hypervisors, storage and I/O virtualization, technologies that would all wind up being used a lot in building the cloud. But on that day, as I approached the end of grad school and the beginning of having a family and a career, the very first external customer objects were starting to land in S3.

Building and Operating a Pretty Big Storage System Called S3

Thu, 27 Jul 2023 00:00:00 +0000

I’ve worked in computer systems software – operating systems, virtualization, storage, networks, and security – for my entire career. However, the last six years working with Amazon Simple Storage Service (S3) have forced me to think about systems in broader terms than I ever have before. In a given week, I get to be involved in everything from hard disk mechanics, firmware, and the physical properties of storage media at one end, to customer-facing performance experience and API expressiveness at the other. And the boundaries of the system are not just technical ones: I’ve had the opportunity to help engineering teams move faster, worked with finance and hardware teams to build cost-following services, and worked with customers to create gob-smackingly cool applications in areas like video streaming, genomics, and generative AI.

My Last First Graduate Lecture of the Year

Mon, 25 Sep 2017 00:00:00 +0000

Every few years, I have the opportunity to teach UBC’s graduate-level “Advanced Operating Systems” course. The course is a breadth requirement for grad students in the department, and so it has a diverse set of students, not just folks who plan to actually do systems research. I like to use the first lecture to position operating systems research much more broadly than just OS kernels, and to take advantage of one of the first lectures that the students get in grad school to share a few ideas about how to get the most out of the next few years.