# Lambda Managed Instances

> Lambda on EC2 capacity you choose, many requests per environment. The middle ground for a steady function that should stay a Lambda.

- Verdict: Watching
- Vendor: AWS
- Layer: [Compute](https://cloudlesslabs.com/stack/layers/compute/index.md). Job: Steady Lambda at volume
- Last reviewed: 25 October 2026, by Nicolas Dao (Cloudless Labs, Sydney)
- Web page: https://cloudlesslabs.com/stack/aws-lambda-managed-instances/. The whole stack in one file: https://cloudlesslabs.com/stack/brief.md

Announced at re:Invent 2025 and in Sydney since June 2026: your function runs on EC2 instances you pick, with many requests per environment, while keeping Lambda's programming model, event sources and deploys. I haven't run it in production, so it's on my watch list.

It answers a real gap. A steady, high-volume function pays classic Lambda for every request's full wait; Managed Instances bill the machine instead, at EC2 prices plus 15%. But it gives up what makes Lambda Lambda: there's no scale to zero, three instances by default, and it throttles when traffic more than doubles within five minutes. So it's for a steady function, not a spiky one. The comparison with a container is in [Lambda, Fargate or EC2?](https://cloudlesslabs.com/stack/guides/lambda-or-containers/index.md).

## Use it when

- A steady function, about 30 requests in flight and up, that you want to keep as a Lambda: same events, same deploys.
- Node.js code that mostly waits: 64 requests per vCPU by default.
- Asynchronous and event-source work that needs up to 90 minutes.

## Don't use it when

- Spiky traffic: it throttles when traffic more than doubles within five minutes.
- Small or idle functions: at least three instances by default, and no scale to zero.
- A plain HTTP service where a container is fine: Fargate is a little cheaper at the same load.

## Pricing

The EC2 instances at normal EC2 rates, plus a 15% management fee on their on-demand price, plus $0.20 per million requests. Sydney: the fee on an m7g.large is $0.0153 an hour. Savings Plans and Reserved Instances cut only the EC2 part. At 50 requests in flight all day, about $560 a month on demand (about $382 with a 3-year plan), against about $1,883 on classic Lambda.

## Gotchas, with fixes

- **Gotcha:** The function needs at least 2 GB and 1 vCPU, and the instances run in your VPC.
  **Fix:** Use public subnets where you can: a NAT gateway adds a fixed monthly cost.
- **Gotcha:** Many requests share one environment, so module-level state is shared between them.
  **Fix:** Keep handlers free of per-request globals before moving a function onto it.

## Provisioning

Official Pulumi package · Official Terraform provider

A capacity provider (aws.lambda.CapacityProvider, Terraform aws_lambda_capacity_provider) attached to the function.

## Instead, consider

- [AWS Lambda](https://cloudlesslabs.com/stack/aws-lambda/index.md): Spiky traffic and anything small.
- [Fargate services (always on)](https://cloudlesslabs.com/stack/aws-fargate-service/index.md): A steady HTTP service that doesn't need to stay a Lambda.
- [Lambda Web Functions](https://cloudlesslabs.com/stack/aws-lambda-web-functions/index.md): HTTP with many requests per environment, once in your region.

## Worked examples

- [Lambda, Fargate or EC2?](https://cloudlesslabs.com/stack/guides/lambda-or-containers/index.md): My Lambda is busy all day, or its reserved concurrency keeps going up. When is it time to move to a container, and where is the line?

## Sources

- [Lambda Managed Instances](https://docs.aws.amazon.com/lambda/latest/dg/lambda-managed-instances.html)
- [Lambda Managed Instances scaling](https://docs.aws.amazon.com/lambda/latest/dg/lambda-managed-instances-scaling.html)
- [Lambda Managed Instances in more regions (June 2026)](https://aws.amazon.com/about-aws/whats-new/2026/06/aws-lambda-managed-instances-region-expansion/)
- [Lambda pricing](https://aws.amazon.com/lambda/pricing/)

## Related

- [Compute](https://cloudlesslabs.com/stack/layers/compute/index.md): every tool in this layer, with its verdict
- [The whole stack in one file](https://cloudlesslabs.com/stack/brief.md): every use case and tool, for questions that span many
- [Map of every Markdown file on cloudlesslabs.com, with what each one answers](https://ask.cloudlesslabs.com)