Cloud Native Product Life Cycle

Day-0 : define, design, modelling (i.e. Design Thinking)
Day-1 : development, installation, configuration, deployment (i.e. CI/CD)
Day-2 : re-configuration, update, backup, failover, restore, etc. (Conflict-needs phase, i.e. extensibility but efficiency and reliability)
IMHO, instead of so called Day, it should be Phase in terms of project management life cycle.
Further reading : What are Day-0, Day-1, and Day-2 Operations?.