docs(day-2): Finished cnpg talk notes

content/day-2/04_operator estensibility.md

@@ -42,4 +42,9 @@ TODO: Steal diagram from slides
 - Reconciler: Interaction during the reconciliation loop -> Stop, Requeue, Continue
 - Metrics Collection: Register additional metrics
 - Backups: Execute the backup
-- WAL Archiving: Handle WAL archiving externally
+- WAL Archiving: Handle WAL archiving externally
+
+## Takeaways
+
+- A good way to move from a monolith to modularity (like csi did for storage maintainance in kubernetes core)
+- Interface first is usually the better choice for long term extensibility