When To Use Aws Lambda Vs Ec2

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As a developer, I often find myself faced with the question of whether to use AWS Lambda or EC2 for different projects. Both services offer unique benefits and it’s important to understand when to use each one. In this article, I will dive deep into the details and provide personal insights and commentary on when to choose AWS Lambda or EC2.

Introduction to AWS Lambda and EC2

AWS Lambda and EC2 are two popular services in Amazon Web Services (AWS) that allow developers to run their applications in the cloud. While they serve a similar purpose, they have distinct differences.

AWS Lambda is a serverless computing service that lets you run your code without provisioning or managing servers. It automatically scales your applications in response to incoming requests, ensuring high availability and cost-effectiveness. Lambda functions are event-driven, meaning they are triggered by events such as API calls, file uploads, or database updates.

On the other hand, Amazon EC2 (Elastic Compute Cloud) provides virtual servers in the cloud. With EC2, you have full control over your virtual servers, including operating system, applications, and security. It offers more flexibility and customization options compared to Lambda but requires manual scaling and management.

When to Use AWS Lambda

AWS Lambda is an excellent choice when you have intermittent or unpredictable workloads. Since Lambda automatically scales based on incoming events, you only pay for the actual execution time of your functions. This makes it cost-effective for applications with sporadic usage patterns.

Lambda is also well-suited for lightweight and event-driven tasks. It is ideal for small to medium-sized applications, microservices, and backend tasks such as data processing, file conversions, and image resizing. With Lambda, you can quickly prototype and deploy code without worrying about infrastructure management.

Another advantage of Lambda is its tight integration with other AWS services. You can easily trigger Lambda functions in response to events from services like S3, DynamoDB, or API Gateway. This seamless integration allows for building serverless architectures and microservice-based applications.

However, Lambda does have some limitations. Each function has a maximum execution time of 15 minutes, which may not be sufficient for long-running tasks. Additionally, cold starts can introduce latency if your function hasn’t been invoked recently. These limitations should be considered when choosing Lambda for your project.

When to Use Amazon EC2

Amazon EC2 is a better fit for applications that require long-running or persistent workloads. If you have a large monolithic application, a legacy system, or you need full control over the underlying infrastructure, EC2 is the way to go.

EC2 allows you to customize your virtual servers to meet specific requirements. You can choose the instance type, storage options, and network configuration. This level of control is useful for applications with complex architectures, high-performance computing, or specialized hardware requirements.

Furthermore, EC2 supports a wide range of operating systems and software stacks. If you need to use a specific version of an operating system or have dependencies that are not compatible with Lambda’s execution environment, EC2 provides the flexibility to meet those requirements.

However, managing EC2 instances requires more effort compared to Lambda. You have to handle scaling, load balancing, and server maintenance yourself. This can be time-consuming, especially if you need to manage a large fleet of instances. It’s important to consider the operational overhead when deciding between Lambda and EC2.


In conclusion, the choice between AWS Lambda and EC2 depends on the specific needs of your application. AWS Lambda offers a serverless, event-driven computing model that is well-suited for lightweight and intermittent workloads. On the other hand, Amazon EC2 provides full control and flexibility but requires manual management and scalability.

When deciding between Lambda vs EC2, consider factors such as workload characteristics, cost efficiency, infrastructure requirements, and management overhead. By carefully evaluating these factors, you can make an informed decision and leverage the right AWS service for your project.