Expected runtime Answer from powderp on reddit.com
Reddit
reddit.com › r/aws › when do you draw a line on lambda vs ecs container?
r/aws on Reddit: When do you draw a line on lambda vs ecs container?
July 7, 2023 -
Lambdas are cheap and powerful, what key factor makes you switch?
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Use containers when expecting your Lambdas to block for more than 25% of their execution time. Blocking = Any reason where CPU won't be utilized. The point of Lambda is to not pay for idle CPU, so don't use it for cases where you will have idle CPU. I see too many devs using it to make blocking calls the 3rd party APIs, slow DB queries, synchronous calls to other Lambdas (grrrr), etc... It's one of the reasons why DynamoDB is more appropriate than RDS. It's also why event based architecture is promoted. If you have more than a trivial amount of blocking calls it's better to stack executions in containers where one call's idle can be used by another call's compute. Keep in mind that you're not likely to keep container nodes above 60% average CPU without scaling and redundancy risks, so you're likely to have a lot of wasted CPU with containers. So the inverse of this rule is true as well. Also don't be afraid to use both containers and Lambdas in the same app. Don't be a victim of the tyrany of 'or' when 'and' is the more benevolent ruler.
AWS
docs.aws.amazon.com › aws decision guides › aws decision guide › aws fargate or aws lambda?
AWS Fargate or AWS Lambda? - AWS Fargate or AWS Lambda?
Reduced operational overhead: Both Lambda and Fargate abstract away server management, reducing the need for patching, maintenance, and capacity planning. Pay-per-use pricing: You only pay for the compute resources you actually use, potentially lowering costs for variable workloads. Faster deployment: Typically offers quicker deployment times compared to provisioning and configuring EC2 ...
Comparing AWS Lambda with Docker and Amazon ECS Fargate: Costs, Testing, and Differences
Re: cost of storing images in ECR — it can add up over time if you’re not clearing old images out. We’re retaining the most recent 5 for most projects, which has worked out fine. More on reddit.com
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August 24, 2023amazon ecs - Fargate vs Lambda, when to use which? - Stack Overflow
I'm pretty new to the whole Serverless landscape, and am trying to wrap my head around when to use Fargate vs Lambda. I am aware that Fargate is a serverless subset of ECS, and Lambda is serverle... More on stackoverflow.com
When do you draw a line on lambda vs ecs container?
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July 7, 2023Why we moved from Lambda to ECS
It sounds like your use case could have been addressed by Step Functions - did you look into it before deciding to switch to ECS? More on reddit.com
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April 20, 2021ECS vs EKS vs Lambda: Which AWS Service to Choose? | Cloud & DevOps ...
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Building Microservices on AWS: Lambda vs ECS Fargate - YouTube
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AWS EC2 vs ECS vs Lambda | Which is right for YOU? - YouTube
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EC2 vs ECS vs Lambda – How to Pick the Right AWS Compute - YouTube
ECS vs EKS vs Lambda: Which AWS Service to Choose ...
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Lambda vs. Fargate Comparison [for Serverless Containers] - YouTube
BMC Software
bmc.com › blogs › aws-ecs-vs-aws-lambda
AWS ECS vs AWS Lambda: What’s The Difference & How To Choose
Clusters and ECS tasks run inside specified AWS Virtual Private Clouds (VPCs) and subnets. AWS Lambda excels at running smaller on-demand applications that are triggered by new events and information.
Sedai
sedai.io › home › blog › comparing aws lambda eks ecs ecs factors in system design and cost management
Lambda vs EKS vs ECS vs EC2: A Practical Comparison | Sedai
March 21, 2026 - Unlike Lambda, which is serverless, EKS provides more control over the orchestration of your containers, making it suitable for larger, more complex applications that require dynamic scaling and high availability.
Medium
medium.com › @moradiyabhavik › aws-compute-services-lambda-vs-ec2-vs-ecs-choosing-the-most-cost-effective-and-highly-available-1cfb410aff1f
AWS Compute Services: Lambda vs EC2 vs ECS — Choosing the Most Cost-Effective and Highly Available Solution | by Bhavik Moradiya | Medium
June 13, 2024 - AWS Lambda is ideal for event-driven, variable workloads where you want minimal operational overhead and cost-efficiency for intermittent usage. Amazon EC2 offers the most control and flexibility, suitable for consistent high-demand workloads ...
Artjoker
artjoker.net › blog › ecs vs eks vs lambda: how to choose the right aws stack for your devops workflow
ECS vs EKS vs Lambda Comparison: Choosing the Right AWS Stack for DevOps | ARTJOKER
July 17, 2025 - ECS (Elastic Container Service) is Amazon’s fully managed container platform – it’s tight with the AWS ecosystem, fast to set up, and handles orchestration for you. EKS (Elastic Kubernetes Service), on the other hand, gives you full Kubernetes control, ideal for teams already deep into the K8s world or looking for cross-cloud portability. Then there’s Lambda – serverless, event-driven, and crazy efficient for the right workloads.
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DEV Community
dev.to › aws-builders › deploying-ml-models-to-production-aws-lambda-vs-ecs-vs-eks-a-data-driven-comparison-8ib
Deploying ML Models to Production: AWS Lambda vs ECS vs EKS - A Data-Driven Comparison - DEV Community
November 11, 2025 - Lambda saves $2,100/year. ... Real-World Example: A B2B SaaS analyzing 50K customer support tickets/day during business hours (9am-6pm). ECS with auto-scaling provides predictable costs (~$75/month) and performance.
Bluelight
bluelight.co › blog › aws-ecs-vs-aws-lambda
AWS ECS vs AWS Lambda: 5 Main Differences
In contrast, AWS Lambda is the better choice if you want a program executed straight away with minimal configuration. These questions should help in making a better decision in choosing a deployment service between AWS ECS vs AWS Lambda.
Published November 11, 2025
CloudZero
cloudzero.com › home › blog › ecs vs. ec2 vs. s3 vs. lambda: the ultimate aws comparison
ECS Vs. EC2 Vs. S3 Vs. Lambda: The Ultimate AWS Comparison
August 29, 2025 - Lambda provides managed serverless computing on Amazon Web Services. ECS is an AWS service that orchestrates Docker containers.
Digital Cloud
digitalcloud.training › home › amazon web services › ecs vs ec2 vs lambda
ECS vs EC2 vs Lambda
December 18, 2025 - With EC2 and Fargate you still have some type of control over the compute engine but with Lambda you forfeit all control for a totally hands-off experience.
Reddit
reddit.com › r/aws › comparing aws lambda with docker and amazon ecs fargate: costs, testing, and differences
r/aws on Reddit: Comparing AWS Lambda with Docker and Amazon ECS Fargate: Costs, Testing, and Differences
August 24, 2023 -
Hi everyone,
I'm fairly new to AWS, and I've been exploring serverless computing with AWS. Specifically, I'm interested in Lambda functions deployed using Docker images. I have a few questions and would appreciate your insights:
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Differences Between Fargate in ECS and Lambda with Docker:
I understand that Lambda is categorized as FaaS, while ECS Fargate is considered as CaaS. Could someone clarify the key differences and when to use one over the other for specific use cases? -
Cost Implications of Storing Docker Images in ECR:
When we store Docker images in Amazon Elastic Container Registry (ECR), does the cost of image storage significantly impact our overall AWS bill? -
Local Testing with Lambda Using Docker:
One notable advantage of Lambda with Docker is the ability to test functions locally. However, what's the recommended approach when our Lambda function interacts with other AWS services, like updating a database in RDS Aurora? How can we simulate such interactions during local testing?
Thanks in advance for your help!
Looking forward to your responses.
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Re: cost of storing images in ECR — it can add up over time if you’re not clearing old images out. We’re retaining the most recent 5 for most projects, which has worked out fine.
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I've been moving from Lambda to ECS with FarGate - cost depends on various things (amount of RAM/CPU to dedicate to Lambda/ECS will probably be the biggest cost) but part of the motivation was better ability to test locally (can just send a curl request to the API in the container rather than trying to use a mock AWS or something to hit a Lambda). AWS charges (in ap-southeast-2 at least) 10c/GB/month which should work out to be pretty cheap as long as you've got automatic clean-up enabled.
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That's the start of a good analogy. However Lambda also has limitations in terms of available CPU and RAM, and a maximum run time of 15 minutes per invocation. So anything that needs more resources, or needs to run for longer than 15 minutes, would be a better fit for Fargate.
Also I'm not sure why you say something is a better fit for Fargate because you "always need at least one instance running". Lambda+API Gateway is a great fit for API calls. API Gateway is always ready to receive the API call and it will then invoke a Lambda function to process it (if the response isn't already cached).
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It is important to notice that with Lambda you don't need to build, secure, or maintain a container. You just worry about the code. Now as mentioned already, Lambda has a max run time limit and 3GB memory limit (CPU increases proportionally). Also if it is used sporadically it may need to be pre-warmed (called on a schedule) for extra performance.
Fargate manages docker containers, which you need to define, maintain and secure. If you need more control of what is available in the environment where your code runs, you could potentially use a container (or a server), but that again comes with the management. You also have more options on Memory/CPU size and length of time your run can take to run.
Even for an API server as you mentioned you could put API gateway in front and call Lambda.
Tocconsulting
tocconsulting.fr › compare › ecs-vs-eks-vs-lambda-vs-apprunner
ECS vs EKS vs Lambda vs App Runner - AWS Compute Comparison | Toc Consulting
Compare AWS ECS, EKS, Lambda, and App Runner. Pricing, complexity, security implications, cold starts, and when to use each compute service on AWS.
Medium
medium.com › @michael-ortiz › aws-lambda-ecs-or-ec2-which-one-should-you-choose-a00615b2b3a8
AWS: Lambda, ECS, or EC2 — Which One Should You Choose? | by Michael Ortiz | Medium
March 3, 2025 - AWS has a hard 15-minute execution limit for each Lambda function. If your process takes longer than that, the function will be terminated and any in-progress tasks will be lost. For most API backends, this is not an issue, as processes tend to be short-lived. However, if you need to run long-running processes, you’ll want to explore alternatives like ECS or EC2, which are better suited for such workloads.
mkdev
mkdev.me › posts › processing-background-jobs-on-aws-lambda-vs-ecs-vs-ecs-fargate
AWS Background Jobs: Lambda vs ECS vs Fargate Cost Analysis
March 1, 2025 - If we look at the per millisecond price, AWS Lambda is almost 4 times more expensive than ECS Fargate Spot. Fargate Spot is so cheap for a reason - those containers can be gone any second, in the middle of your background job.
Quora
quora.com › How-does-AWS-Lambda-work-and-why-is-it-faster-than-Amazon-Elastic-Compute-Cloud-EC2-instances-for-executing-code-snippets
How does AWS Lambda work and why is it faster than Amazon Elastic Compute Cloud (EC2) instances for executing code snippets? - Quora
Answer: Lambdas work by executing your code on servers that you don’t manage or even see. That is why lambdas are part of the world of serverless computing. Their lifecycle is managed by AWS in that a new instance is created when required and destroyed thereafter.
Stormit
stormit.cloud › blog › amazon-fargate-vs-aws-lambda
AWS Fargate vs. AWS Lambda: Key Differences Explained
February 9, 2026 - You need support for custom dependencies, libraries, or OS-level tooling not available in Lambda runtimes. Your team is already working with Docker or container-native tooling and wants to scale without managing EC2 infrastructure.
Hakky Handbook
book.st-hakky.com › hakky handbook › ec2 vs ecs vs lambda: a comparison from the perspective of api serving
EC2 vs ECS vs Lambda: A Comparison from the Perspective of API Serving | Hakky Handbook
April 4, 2026 - While EC2 can reduce costs by purchasing reserved instances, it requires more management and maintenance and can be more expensive than ECS or Lambda. ECS allows easy container management and automatic scaling based on traffic changes.
DevOps.dev
blog.devops.dev › aws-lambda-vs-fargate-a-practical-guide-to-choosing-the-right-serverless-compute-e3625adea2b7
AWS Lambda vs Fargate — A Practical Guide to Choosing the ...
April 20, 2026 - Devops.dev is a community of DevOps enthusiasts sharing insight, stories, and the latest development in the field.
Edge Delta
edgedelta.com › home › company › knowledge center › fargate vs lambda architecture performance cost and more
Fargate vs. Lambda: Architecture, Performance, Cost, And More
March 13, 2025 - Architecture is one of the critical differences between Fargate and Lambda. With Fargate, you’ll have a simplified way of running containers with ECS or EKS.