Azure Services: A Tech Team Quick Reference Page

Azure Services: A Tech Team Quick Reference
A condensed, decision-focused guide to the major Azure service categories
By Swedel F Menezes - Cloud Team
A condensed, decision-focused guide to the major Azure service categories. For each service: what it is, primary use cases, and a one-line “when to choose it” rule. Use this as a quick reference when designing or reviewing an Azure architecture.
Azure Reference Architecture — Layer Overview
Layer
Service(s)
Role
Edge / Ingress
Azure Front Door
Global HTTP load balancing, CDN, WAF & intelligent routing
Web / API Compute
App Service
Managed PaaS for web apps, REST APIs and mobile backends
Container Compute
AKS (Kubernetes)
Orchestrated containers, microservices, auto-scaling
Serverless Compute
Azure Functions
Event-driven, short-lived tasks triggered by HTTP/queue/blob
Relational Data
Azure SQL Database
Managed SQL Server — structured OLTP workloads
NoSQL / Global Data
Cosmos DB
Multi-model, globally distributed, <10 ms latency
Object Storage
Blob Storage
Unstructured data — media, backups, analytics staging
Caching
Azure Cache for Redis
Sub-millisecond in-memory caching & session state
Identity
Microsoft Entra ID
SSO, MFA, app registrations & managed identities
Secrets
Key Vault
Centralised store for secrets, keys & TLS certificates
Observability
Azure Monitor + App Insights
Full-stack metrics, logs, alerts & distributed tracing
Security Posture
Defender for Cloud
CSPM scoring, threat detection & compliance dashboards
1. Compute
Service
What it is & key use cases
When to choose it
Virtual Machines (VMs)
IaaS with full OS control. Lift-and-shift, legacy apps, custom OS, dev/test.
You need full OS control or have compliance/legacy needs that block PaaS.
App Service
Managed PaaS for web apps & REST APIs. ASP.NET/Node/Python/Java, auto-scale, CI/CD.
You want to focus on code, not infra, and don’t need container orchestration.
Azure Kubernetes Service (AKS)
Managed Kubernetes for containers. Microservices, auto-scaling, self-healing.
You run multiple containers needing orchestration & service discovery.
Container Instances (ACI)
Serverless single containers. Batch jobs, CI tasks, quick tests.
Simple isolated container tasks; use AKS if you need orchestration.
Azure Functions
Event-driven serverless compute. HTTP APIs, timers, queue/blob events.
Short-lived, event-triggered work. Avoid for long-running (>10 min) jobs.
2. Storage
Service
What it is & key use cases
When to choose it
Blob Storage
Object storage for unstructured data. Static sites, media, backups, analytics staging.
Any binary/unstructured data. Hot/Cool/Archive tiers by access frequency.
Azure Files
Managed SMB/NFS file shares. Replace on-prem file servers, shared config.
Apps that need a shared file system; use Blob for object storage.
Data Lake Storage Gen2
Blob + hierarchical namespace for big data. ML data, ETL, Synapse/Databricks.
Big-data workloads needing directory-level ACLs and hierarchy.
3. Networking
Service
What it is & key use cases
When to choose it
Virtual Network (VNet)
Isolated private network — foundation of secure deployments.
Always for production. Never expose resources without NSG rules.
Load Balancer
Layer 4 (TCP/UDP) balancing across VMs. HA, inbound NAT, internal LB.
Non-HTTP VM workloads needing HA; use App Gateway for HTTP.
Application Gateway
Layer 7 (HTTP/S) LB with WAF, SSL termination, URL routing.
HTTP/S apps needing WAF, SSL offload, or path-based routing (regional).
Front Door
Global HTTP LB with CDN, WAF, intelligent routing.
Global apps needing low latency worldwide + edge CDN/failover.
VPN Gateway
Site-to-site / point-to-site VPN to on-prem. Hybrid cloud, remote access.
Encrypted hybrid connectivity; use ExpressRoute for dedicated bandwidth.
4. Databases
Service
What it is & key use cases
When to choose it
Azure SQL Database
Managed relational PaaS (SQL Server engine). Web/enterprise OLTP, migrations.
Structured relational data. Elastic Pool for many DBs, MI for full compat.
Cosmos DB
Globally distributed multi-model NoSQL. IoT, catalogs, gaming, multi-region writes.
You need <10ms global latency, flexible schema, or active-active replication.
Azure Cache for Redis
Managed in-memory cache. Session state, query caching, leaderboards, pub/sub.
App has repetitive expensive queries or needs sub-millisecond responses.
Synapse Analytics
Unified data warehouse + big data analytics. ETL/ELT, BI, Power BI/ML.
Large-scale analytical workloads; use Azure SQL for operational OLTP.
5. AI & Machine Learning
Service
What it is & key use cases
When to choose it
Azure Machine Learning
End-to-end ML platform. Custom models, AutoML, MLOps, monitoring/retraining.
Building custom models; use AI Services for pre-built capabilities.
Azure AI Services
Pre-built AI APIs — Vision, Speech, Language, Decision. OCR, sentiment, STT/TTS.
You need AI features fast via REST without training custom models.
Azure OpenAI Service
OpenAI models (GPT, DALL-E, Whisper, embeddings) in Azure. Chatbots, summarization, code, semantic search.
You need enterprise security, private networking, compliance & data residency.
6. DevOps & Monitoring
Service
What it is & key use cases
When to choose it
Azure DevOps
Boards, Repos, Pipelines, Test Plans, Artifacts. CI/CD, agile, source control.
End-to-end DevOps lifecycle integrated with the Azure ecosystem.
Key Vault
Secure store for secrets, keys, certificates. Connection strings, TLS certs, CMK.
Always — never hardcode credentials. Access via managed identity.
Monitor & App Insights
Full-stack observability — metrics, logs, alerts, APM, distributed tracing.
Enable on every app/Function from day one; retro-fitting is harder.
7. Security & Identity
Service
What it is & key use cases
When to choose it
Microsoft Entra ID
Cloud identity & access (IAM). SSO, MFA, app registrations, managed identities.
Always for authentication; use managed identities for service-to-service auth.
Defender for Cloud
CSPM + workload protection. Posture scoring, threat detection, compliance.
Enable on all production subscriptions for a unified security view.
Microsoft Sentinel
Cloud-native SIEM + SOAR. Event aggregation, AI analytics, automated response.
Centralized security monitoring across Azure + on-prem + multi-cloud.
8. Integration & Messaging
Service
What it is & key use cases
When to choose it
Service Bus
Enterprise broker — queues & topics (pub/sub). Decoupling, dead-lettering, ordering.
Reliable, ordered, transactional messaging; use Event Hubs for streaming.
Event Hubs
Big-data event streaming (millions/sec). IoT telemetry, logs, click-streams.
High-volume event ingestion feeding analytics pipelines.
Logic Apps
Low-code workflow automation, 400+ connectors. B2B, approvals, SaaS integration.
Integration workflows across SaaS/enterprise; use Functions for custom code.
API Management (APIM)
Full-lifecycle API gateway. Publish, secure, throttle, version, dev portal.
Exposing APIs externally or across teams with governance & observability.
9. Analytics
Service
What it is & key use cases
When to choose it
Azure Databricks
Spark-based analytics platform. Large ETL, ML at scale, streaming, lakehouse.
Complex big-data processing with Spark; integrates with ADLS Gen2 & Synapse.
Data Factory (ADF)
Cloud-scale ETL/ELT integration. Pipeline orchestration, 90+ connectors.
The orchestration layer of your data platform; moving data on-prem ↔ cloud.
Service Selection Decision Tree
What kind of workload?
 
Run application code
Event-driven → Functions
Web app / API → App Service
Containers at scale → AKS
Full OS control → VMs
Store / query data
Relational / OLTP → Azure SQL
Global NoSQL → Cosmos DB
Files / blobs → Blob Storage
Analytics / DW → Synapse
Connect / process events
Reliable queue → Service Bus
High-volume stream → Event Hubs
Low-code workflow → Logic Apps
Publish APIs → API Management
Always add: Entra ID (identity) • Key Vault (secrets) • Monitor + App Insights (observability)
Figure 2 — Decision tree mapping a workload type to the recommended Azure service.
Service Selection Quick Reference
Need
Service
Host a web app
App Service
Run containers at scale
AKS
Simple container task
ACI
Serverless function
Azure Functions
Relational DB
Azure SQL Database
NoSQL / Global DB
Cosmos DB
Cache
Azure Cache for Redis
Data warehouse
Synapse Analytics
Big data processing
Databricks
ETL orchestration
Data Factory
Store files/blobs
Blob Storage
Shared file system
Azure Files
Pre-built AI APIs
Azure AI Services
Custom ML models
Azure ML
LLM / GPT
Azure OpenAI
Message queue
Service Bus
Event streaming
Event Hubs
API gateway
API Management
Secrets management
Key Vault
Identity / SSO
Microsoft Entra ID
Security posture
Defender for Cloud
SIEM
Microsoft Sentinel
Monitoring / APM
Azure Monitor + App Insights