As of Fri 2019-06-07, I manage the Treeherder group inside Joel Maher's CI-Automation team. Co-ordinating with the Code Sheriffs, we check that the code committed to Firefox does not cause regressions or other errors.
I am SF Bay Area-based; my desk is #7010, on the non-kitchen side of the 7th floor in SF. (When I'm in MTV, I usually sit just off the kitchen on the away-from-Evelyn-Avenue side of the second floor.) However, since becoming a manager, I am hardly ever at my desk anymore; email and IRC are far more effective (I don't pay attention to Slack until it sends me an email notification.) I keep my calendar up-to-date; a calendar invite is by far the best way to book some of my time. Please don't phone me unless it's already an emergency; cell phones in particular make it very difficult for me to understand you.
I start and end the day early these days; on a typical day I will start having meetings at 7am Pacific (15:00 UTC), and sometimes earlier. I try to wrap up by 3pm Pacific (23:00 UTC); if you're in Asia or Oceania and need to book a meeting, let's see what we can work out.