Lambda Function
By Pooja | 2nd July 2025
What is Lambda Function?
AWS Lambda Use Case Examples
Amazon Web Services (AWS) offers a serverless computing solution called AWS Lambda that lets you run your code without having to provision or manage servers.
Lambda handles everything needed to run and scale your code with high availability; all you have to do is upload your code and set the conditions to trigger it.
In summary: Create your code, upload it, and AWS will execute it when prompted; there are no servers to maintain.
Essential Elements of AWS Lambda
- Serverless: No management or provisioning of servers is required.
- Event-Driven: Code is executed in reaction to various events, such as database updates, file uploads, and API requests.
- Auto-Scaling: Adjusts automatically according to the volume of requests received.
- Cost-effective: You only have to pay for the computation time that your code requires.
- Supports a variety of languages, including Ruby, C#, Python, Java, Go, and Node.js.
- Integrated security: Provides safe access control by integrating with AWS Identity and Access Management (IAM).
The Basic Architecture of How AWS Lambda Operates
This is how AWS Lambda functions:
- Write your code, also known as a Lambda function.
- Use the console, CLI, or SDK to upload it to AWS Lambda.
- Configure a trigger, which could be a DynamoDB stream, an S3 bucket event, an API call, etc.
- When the trigger is triggered, AWS Lambda executes your function.
- Lambda scales automatically by executing additional parallel instances of the function as required.
- You only pay for the milliseconds that your code executes.
Diagram:
📦 Event Source → 🔁 AWS Lambda → 📤 Process / Response / Store
You may also be interested in our blog on Introduction to Serverless Computing.
- Web Application Backend: Use Lambda and Amazon API Gateway to run serverless APIs.
- Real-Time File Processing: Process documents, videos, or photos uploaded to S3 automatically.
- Database Triggers: Provide real-time notifications in response to modifications in DynamoDB tables.
- Scheduled Tasks (Cron jobs): Use Amazon CloudWatch Events to carry out regular maintenance duties.
- Handle real-time data from IoT sensors by processing IoT data.
- Voice Assistant and Chatbot Skills: Backend operations for chatbot logic or Alexa skills.
Example:
Hello World Lambda Function (Python)
def lambda_handler(event, context):
return {
‘statusCode’: 200,
‘body’: ‘Hello, World from AWS Lambda!’
}
BENEFITS:
- No infrastructure management;
- Automatic scaling;
- High availability;
- Granular pricing structure;
- Simple integration with other AWS services
RESTRICTIONS:
- Execution time is limited to 15 minutes.
- Cold start delays (for rarely used functions);
- Resource limits (memory up to 10 GB);
- Stateless (no local storage between invocations);
Conclusion:
By eliminating the need to manage servers, AWS Lambda is a potent service that streamlines application development. It is perfect for developers and companies looking for affordable, scalable, and highly available application solutions because of its event-driven nature and pay-as-you-go business model.
AWS Lambda provides a versatile and effective way to run your code in the cloud, whether you’re developing a web application, automating backend tasks, or processing data streams in real-time.
Explore more on Cloud Computing Services by AWS to get the full picture.