⚖️ Logic Apps vs Azure Functions: Comparison Overview
| Feature / Aspect | Logic Apps | Azure Functions |
|---|---|---|
| Type | Low-code orchestration tool | Serverless code execution |
| Audience | Citizen devs, integrators | Developers (C#, JS, Python, PowerShell, etc.) |
| Development Environment | Visual Designer (Portal) | Visual Studio, VS Code, Azure Portal |
| Use Case | Workflow-based integrations (connectors) | Custom code, APIs, backend processing |
| Triggers | Event-based (HTTP, schedule, connectors) | Event-based (HTTP, Timer, Queue, Service Bus) |
| Connectors | 600+ built-in (Salesforce, SAP, SQL, D365, etc.) | Use SDKs or custom HTTP calls |
| Error Handling | Built-in retry policies, run history UI | Requires manual try/catch, custom retry logic |
| Monitoring | Portal-based run history and alerts | Application Insights, Log Analytics |
| Cost Model | Per action + connector usage | Per execution time and memory usage |
| Governance | DLP policies available in Power Platform | Managed via Azure RBAC and policy controls |
| Security | Managed Identity, OAuth, Key Vault | Managed Identity, OAuth, Key Vault |
✅ When to Use Logic Apps
Think workflow orchestration and low-code integration.
Best For:
Rapid integration with Dynamics 365, BC, SQL, SAP, SharePoint
Non-developer teams (BA/Integration team)
Event-driven workflows like:
On new CRM record → Send Teams alert
On file in SharePoint → Trigger approval
API orchestration across SaaS (email, databases, CRM)
Pros:
Quick to build
Rich out-of-the-box connectors
No infrastructure management
Retry policies, timeouts, conditions—easy to set
Cons:
Limited control over logic complexity
Can be expensive at scale (many actions)
Difficult to test and debug for advanced logic
✅ When to Use Azure Functions
Think custom logic and developer-controlled processes.
Best For:
Complex business rules or custom data transformations
Consuming custom or unsupported APIs
Validating or enriching data from CRM before external sync
Handling Service Bus queue or topic messages
Building microservices to extend CRM
Pros:
Full control over logic, libraries, packages
Ideal for backend event processing
Easily unit testable and source-controllable
Cost-effective at large scale
Cons:
Requires developer skillset
Error handling must be coded
Integration with connectors must be manual (via SDKs or REST)
🔁 Combined Usage Example
Scenario: Sync Dynamics 365 Contact to ERP System
Step 1: Contact is created in D365 → triggers Power Automate / Plugin
Step 2: Send message to Azure Service Bus
Step 3: Azure Function reads from queue, formats payload
Step 4: Call Logic App that connects to ERP API securely using connector
Step 5: Response is logged, notification sent via Teams
This combo lets you offload complex logic to Functions, while reusing connectors in Logic Apps for third-party integration.
🎯 Interview Tips
Expect questions like:
When would you choose Azure Functions over Logic Apps?
How do you secure them?
How do you manage failures, retries, and observability?
Can you describe a real-world architecture using both?