Azure Look-Alikes Explained: Quick Choices for Real-World Designs

If you’ve ever paused mid design wondering “which Azure thing is this again?” you’re not alone. The ecosystem is huge, the names are similar, and even senior engineers double-check. This guide clears it up with quick, practical comparisons—so you can choose faster and ship with confidence.

Service Endpoints vs Private Endpoints

  • Service Endpoint: Your subnet can reach a PaaS service at its public IP, but over Microsoft’s backbone. You “allow” that subnet on the service side.
  • Private Endpoint: You get a private IP for one specific resource/sub-resource (e.g., Storage Blob vs Queue), injected into your VNet; traffic never hits the public IP

Managed Identity vs Service Principal

  • Managed Identity (MI): Azure creates/rotates credentials for you; identity is tied to a particular resource (system-assigned) or stands alone and reusable (user-assigned).
  • Service Principal (SP): Identity for an app registration you create; you manage the credentials (secret or cert) or use workload identity federation (no long-lived secret) for CI/CD processes.

Azure Network Security Groups(NSG) vs Azure Firewall

  • NSG: Stateful L3/L4 allow/deny rules on subnets with lightweight isolation. These are typically per subnet and offer simple segmentation.
  • Azure Firewall: Managed, centralized L3–L7 firewall with DNAT/SNAT, FQDN/URL filtering, and Premium features like TLS inspection. It’s Hub-and-spoke friendly, offers Egress governance, application-aware rules and centralized NAT.

Availability Sets vs Availability Zones

  • Availability Set: Spreads VMs across fault and update domains inside one datacenter (up to 3 FDs / 20 UDs). Low latency between members; protects from rack/host failures and co-ordinated updates. It’s ideal for single-site, latency-sensitive tiers (e.g., stateful clusters).
  • Availability Zones: Place resources across separate datacenters in a region. Two+ zone-spanned VMs get a 99.99% VM connectivity SLA. It’s important to mention that data transfer between zones in the same region is now free. It’s ideal for higher fault isolation and regional resilience.