# Inefficient Lambda pricing model for steady high-volume workloads (use Lambda managed instances) Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/inefficient-lambda-pricing-for-steady-high-volume-workloads-use-lambda-managed-instances A function has steady, high-volume traffic (or predictable load) but continues running on default Lambda pricing, where costs scale with execution... By: Andrew Shieh [Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) # Inefficient Lambda Pricing Model for Steady High-Volume Workloads (Use Lambda Managed Instances) The short version A function has steady, high-volume traffic (or predictable load) but continues running on default Lambda pricing, where costs scale with execution duration. [Andrew Shieh](https://www.linkedin.com/in/shandrew/) Principal Engineer / Director of Engineering, Operations @ SmugMug AWS service [AWS Lambda](https://www.pointfive.co/efficiency-hub/cloud-services/aws-lambda) Category [Compute](https://www.pointfive.co/efficiency-hub/service-category/compute) Reference CER-0296 Type Suboptimal Pricing Model ## Explanation Why the waste happens and who it affects. Lambda Managed Instances runs Lambda on EC2 capacity managed by Lambda and supports multi-concurrent invocations within the same execution environment, which can materially improve utilization for suitable workloads (often IO-heavy services). For these steady-state patterns, shifting from duration-based billing to instance-based billing (and potentially leveraging EC2 pricing options like Savings Plans or Reserved Instances) can reduce total cost - while keeping the Lambda programming model. Savings are workload-dependent and not guaranteed. ## Billing model The pricing dimensions that drive this cost. Default Lambda charges per request and per-request execution duration. Lambda Managed Instances charges per request plus EC2 instance charges and a Lambda management fee, and does not charge separately per-request duration. ## How to detect 4 checks to find it in your estate. - Review whether the function has sustained, predictable traffic rather than bursty "scale-to-zero" patterns - Assess whether paying for per-request duration is a dominant cost driver for the workload - Evaluate whether the workload can benefit from multi-concurrent processing (e.g., IO-heavy request handling) - Confirm the workload can tolerate a minimum always-on capacity model (i.e., it is not primarily cost-optimized by being idle most of the time) ## How to fix 3 ways to remove the waste. - Consider Lambda Managed Instances for steady-state, predictable workloads where instance-based pricing and multi-concurrency can improve price-performance - Validate cost and operational fit by comparing expected instance-based spend (including management fee) versus current duration-based Lambda spend before broad adoption - Use default Lambda for bursty or sporadic workloads that benefit most from scale-to-zero economics ## Documentation Vendor references for pricing and configuration. - [https://aws.amazon.com/lambda/pricing/ aws.amazon.com](https://aws.amazon.com/lambda/pricing/) - [https://docs.aws.amazon.com/lambda/latest/dg/lambda-managed-instances.html docs.aws.amazon.com](https://docs.aws.amazon.com/lambda/latest/dg/lambda-managed-instances.html) - [https://docs.aws.amazon.com/lambda/latest/dg/lambda-managed-instances-execution-environment.html docs.aws.amazon.com](https://docs.aws.amazon.com/lambda/latest/dg/lambda-managed-instances-execution-environment.html) - [https://aws.amazon.com/about-aws/whats-new/2025/11/aws-lambda-managed-instances/ aws.amazon.com](https://aws.amazon.com/about-aws/whats-new/2025/11/aws-lambda-managed-instances/) ## Related inefficiencies [Browse the library](https://www.pointfive.co/efficiency-hub) - AWS Lambda CER-0124 ### [Overreliance on Lambda at Sustained Scale](https://www.pointfive.co/efficiency-hub/inefficiencies/overreliance-on-lambda-at-sustained-scale) Lambda is designed for simplicity and elasticity, but its pricing model becomes expensive at scale. When a function runs frequently (e.g., millions of invocations per day) or for extended durations, the cumulative cost may exceed that of... Compute - AWS Lambda CER-0290 ### [Unnecessary Lambda Provisioned Concurrency on Low-Utilization Functions](https://www.pointfive.co/efficiency-hub/inefficiencies/unnecessary-lambda-provisioned-concurrency-on-low-utilization-functions) Provisioned Concurrency is enabled for Lambda functions that do not require consistently low latency or steady traffic. In such cases, provisioned concurrency remains allocated and billed during idle periods, creating ongoing cost without... Compute - AWS Lambda CER-0209 ### [Unnecessary Costs from Unused Lambda Versions with SnapStart](https://www.pointfive.co/efficiency-hub/inefficiencies/unnecessary-costs-from-unused-lambda-versions-with-snapstart) Many teams publish new Lambda versions frequently (e.g., through CI/CD pipelines) but do not clean up old ones. When SnapStart is enabled on Python or .NET functions, each of these versions retains a cached snapshot, generating ongoing... Compute --- Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.