Aaron Gable

Chromium Infrastructure

The Chromium project runs what is, as far as I know, the largest open-source continuous integration build and test automation system in the world. We call it Luci.

The pre-submit system (the "Commit Queue") processes 1,500 commits per day, building and testing each one on a minimum of 25 different platform configurations and running almost 900 parallel hours of tests on a fleet of over 15,000 hosts. The post-submit system encompasses over 500 different platform configurations. And that's all just for the main chromium repository itself, not including any of its 200+ dependencies, many of which we also run CI systems for.

Since early 2019, I have been Technical Lead and manager of the team responsible for the configuration, capacity planning, and performance improvements of this entire system. Over the course of that year we improved the median wall-clock run time of the CQ by 20% (from 48 to 38 minutes). We also expanded both the pre-submit and post-submit systems to cover Chromium's release branches, increasing overall throughput by 11% without increasing cost.

Computer Science Education

I spent fall semester of 2018 teaching Introduction to Computer Science at Xavier University of Louisiana through the Googler in Residence program.

The GIR program sends experienced software engineers to teach at Historically Black Colleges and Universities such as XULA in order to support greater diversity in the tech industry. Over the course of the semester I was able to introduce a generation of new students to the fundamentals of computer science via Python.

I have experience in curriculum development, including writing an entire introductory course from scratch: syllabus, lesson plans, lectures, quizzes, homework, projects, and exams. I also hosted interview prep sessions, tutored individual students, and hosted one wild hackathon (see above).

As a result, a record number of students from Xavier landed summer internships with major tech companies, and the students and program at Xavier continue to grow.

Chromium Developer Tools

Monorail is the bug and issue tracking system used by the Chromium project, as well as a variety of related projects. Since 2016 it has hosted over 1,000,000 issues and 3,000 daily active users for Chromium alone, facilitating collaboration between engineers, engagement with the community, and improvements to the product.

I was one of the creators of Monorail, to replace the Google Code issue tracker when it was being shut down in 2015. I wrote features, designed and executed the data migration, and open-sourced the whole codebase.

I continued to own, develop, and maintain Monorail until late 2018. During that time I also owned our entire developer workflow stack, including our command-line SDK, our code search and indexing system, and our code review tool. During this time I also managed and grew a team of 3 other engineers to work on our developer tools.