Serverless functions
Lambda provisioned concurrency / Lambda SnapStart vs Azure Functions Flex Consumption plan / Azure Functions Premium & Dedicated plans
Lambda provisioned concurrency and SnapStart map to always-ready instances in Azure Functions (Flex Consumption and Premium plans).
Azure has no snapshot-restore equivalent of SnapStart.
Side-by-side comparison
| Aspect | Amazon Web Services | Microsoft Azure |
|---|---|---|
| Service | Lambda provisioned concurrency Lambda SnapStart | Azure Functions Flex Consumption plan Azure Functions Premium & Dedicated plans |
| Lifecycle | Generally available Generally available | Generally available Generally available |
| What it is | Keeps a set number of execution environments initialized for a function version or alias, so requests skip cold starts. Can be scaled with Application Auto Scaling. Lambda snapshots (Firecracker) the initialized execution environment when you publish a version and resumes from the cache on cold starts. Supports Java 11+, Python 3.12+, and .NET 8+. | Linux serverless plan with per-instance concurrency, selectable instance memory (512 MB and up), VNet integration, scale-out up to 1,000 instances, and optional always-ready instances. Premium (Elastic Premium) has always-ready and prewarmed instances, VNet integration, and no cold starts on warm instances. Dedicated runs functions on App Service plans you already pay for. |
| Pricing model | Provisioned concurrency is billed per GB-second configured, plus a lower duration rate. SnapStart has no extra charge for Java but charges caching and restore for Python and .NET. | Always-ready instances in Flex Consumption are billed for baseline memory time plus execution. Premium bills for minimum instances continuously. |
| Docs | Lambda provisioned concurrency docs Lambda SnapStart docs | Azure Functions Flex Consumption plan docs Azure Functions Premium & Dedicated plans docs |
| Pricing page | Lambda provisioned concurrency pricing Lambda SnapStart pricing | Azure Functions Flex Consumption plan pricing Azure Functions Premium & Dedicated plans pricing |
| Exams | DVA-C02 Retiring | AZ-204 Retired |
Key differences
- Pre-warming. Provisioned concurrency keeps N initialized environments per version or alias and can be scaled on a schedule or by target tracking. Azure always-ready instances keep a baseline of instances per function or group (Flex) or per app (Premium, which also has prewarmed buffer instances).
- Snapshots. SnapStart snapshots the initialized environment (Java 11+, Python 3.12+, .NET 8+) and restores it on cold start. Azure has nothing comparable, so reduce init time in code or keep instances warm.
- Lambda Managed Instances avoid cold starts by running on dedicated EC2 capacity. The closest Azure parallel is the Premium or Dedicated plan.
Pricing summary
Pricing models only. No prices are quoted because they change by region and over time.
- AWS
- Provisioned concurrency is billed per GB-second configured, plus a lower duration rate. SnapStart has no extra charge for Java but charges caching and restore for Python and .NET. Lambda provisioned concurrency pricing → Lambda SnapStart pricing →
- Azure
- Always-ready instances in Flex Consumption are billed for baseline memory time plus execution. Premium bills for minimum instances continuously. Azure Functions Flex Consumption plan pricing → Azure Functions Premium & Dedicated plans pricing →
Certification exam mapping
| Exam | Provider | Level | Status |
|---|---|---|---|
| AWS Certified Developer – Associate DVA-C02 | AWS | Associate | retiring Being updated to DVA-C03. Registration for DVA-C03 opens Oct 27, 2026. Last day to take DVA-C02 is Nov 30, 2026. |
| Microsoft Certified – Azure Developer Associate AZ-204 | Azure | Associate | retired The certification and renewal assessment are retired (the page doesn't give a date). The closest current developer credential is AI-200 (Azure AI Cloud Developer Associate). That's our reading, not an official mapping. |
Relevance is based on each exam's published scope, not a line-by-line objective match. Check the official study guide.
Verification notes
- SnapStart pricing for Python and .NET (caching plus restore charges) is summarized from the Lambda pricing page's structure.
FAQ
What is the Azure equivalent of Lambda provisioned concurrency and Lambda SnapStart?
Lambda provisioned concurrency and SnapStart map to always-ready instances in Azure Functions (Flex Consumption and Premium plans). Azure has no snapshot-restore equivalent of SnapStart.
How does pricing compare between Lambda provisioned concurrency and Lambda SnapStart and Azure Functions Flex Consumption plan and Azure Functions Premium & Dedicated plans?
AWS: Provisioned concurrency is billed per GB-second configured, plus a lower duration rate. SnapStart has no extra charge for Java but charges caching and restore for Python and .NET. Azure: Always-ready instances in Flex Consumption are billed for baseline memory time plus execution. Premium bills for minimum instances continuously. Check the official pricing pages for current rates.
Which certification exams cover this topic?
AWS Certified Developer – Associate (DVA-C02) [retiring]; Microsoft Certified – Azure Developer Associate (AZ-204) [retired].