On-Call
Every active engineer has the duty to participate in the on-call organization after their trial period - expectations, rotations/shifts, compensation, etc. is governed by the 24x7 Operations.
Exemptions from this duty have to be requested from People Operations (for example medical reasons). People Operations review active exemptions every 6 months if reasonable.
Important wiki pages
VIP-144 - On-Call Organization (compensation documented here)