Microsoft Azure Last-Minute Revision

30 quick revision notes for Microsoft Azure

1. The Azure hierarchy is tenant, management groups, subscriptions, resource groups and resources; policy and RBAC inherit downward.
2. Microsoft Entra ID is the new name of Azure Active Directory and handles identity, MFA and Conditional Access.
3. A resource belongs to exactly one resource group, groups cannot be nested, and deleting a group deletes its resources.
4. Availability sets give a 99.95% VM SLA; spreading VMs across availability zones gives 99.99%.
5. Composite SLA for dependent services is the product of their individual SLAs, so more serial dependencies lower availability.
6. India has Central India (Pune), South India (Chennai) and West India (Mumbai) public Azure regions.
7. Storage redundancy options are LRS, ZRS, GRS, GZRS and read-access variants RA-GRS and RA-GZRS.
8. Blob tiers are Hot, Cool (30-day minimum), Cold (90-day minimum) and Archive (180-day minimum, offline).
9. A user delegation SAS signed with Entra ID credentials is the most secure type of shared access signature.
10. NSG rules are processed by priority from 100 to 4096, lowest number first, and are stateful.
11. VNet peering is not transitive; spoke-to-spoke traffic needs a hub firewall or appliance with user-defined routes.
12. Azure reserves five IP addresses in every subnet: network, gateway, two for DNS and broadcast.
13. Load Balancer is layer 4 regional, Application Gateway is layer 7 regional, Front Door is layer 7 global.
14. Private endpoints give a PaaS resource a private IP in your VNet and need a privatelink private DNS zone.
15. Managed identities remove secrets from code; system-assigned dies with the resource, user-assigned is standalone.
16. Owner manages resources and access, Contributor manages resources only, Reader only views them.
17. Azure Policy controls what can be deployed; RBAC controls who can perform actions.
18. PIM gives just-in-time, time-bound privileged role activation with approval, MFA and audit.
19. Key Vault stores secrets, keys and certificates; soft delete is always on and purge protection blocks permanent deletion.
20. Azure SQL Database point-in-time restore covers 1 to 35 days; long-term retention keeps backups up to 10 years.
21. Failover groups give stable listener endpoints so apps keep the same connection string after regional failover.
22. Cosmos DB charges in request units; a 1 KB point read costs about 1 RU and excess requests return HTTP 429.
23. Cosmos DB consistency levels are strong, bounded staleness, session (default), consistent prefix and eventual.
24. A Cosmos DB logical partition can hold up to 20 GB, so choose a high-cardinality partition key.
25. Bicep compiles to ARM JSON and needs no state file; Terraform needs secure remote state with locking.
26. Incremental is the default ARM deployment mode; complete mode deletes resources missing from the template.
27. Workload identity federation lets GitHub Actions and pipelines get Azure tokens through OIDC without secrets.
28. Azure Monitor stores metrics for 93 days; logs go to Log Analytics workspaces and are queried with KQL.
29. The activity log records control-plane operations for 90 days; resource logs need diagnostic settings.
30. RPO is acceptable data loss and RTO is acceptable downtime; Site Recovery replicates VMs for regional DR.

Night-before checklist

• Revise your saved questions on this page once, aloud.
• Read the quick notes and mark any you cannot explain in one line.
• Rehearse a two-minute self-introduction and two project stories.
• Keep CV, ID, laptop charger and interview link ready; sleep on time.