CIDuty/Reconfigs
Buildduty is responsible for reconfig-ing the Buildbot masters to get release engineering code changes into production.
The person doing reconfigs should also update the reconfig deployments page.
Scheduled reconfigs
Scheduled reconfigs are *supposed* to happen every Monday and Thursday. During this, buildduty needs to merge default -> production branches and reconfig the affected masters. The Landing Buildbot Master Changes wiki page has step by step instructions.
It is also valid to do other additional reconfigs anytime you want. Other release engineers may have important changes to land that don't coincide with the scheduled reconfigs.
It is polite to ask in #mozbuild if anyone has further changes to land before starting the reconfig process.
How to reconfig
You should use Fabric to do the reconfig.
Help, my reconfig is stuck!
If the reconfig gets stuck, see How To/Unstick a Stuck Slave From A Master.