Serverless Applications: Running Code Without Managing Servers

Serverless computing lets you run code without managing servers, automatically scaling with demand. It reduces operational overhead and costs for event-driven or short-lived tasks.

Table of Contents

• Serverless Applications

Serverless Applications

Serverless Applications execute functions in response to events, with the cloud provider handling infrastructure.

Why it is useful: It eliminates server management and scales automatically, making it ideal for APIs, callbacks, and batch jobs.

Example (AWS Lambda in Python):

# lambda_function.py
import json

def handler(event, context):
    return {
        "statusCode": 200,
        "body": json.dumps({"message": "Hello from serverless"})
    }

This function can be invoked via the AWS CLI:

aws lambda invoke --function-name MyFunction --payload '{"key":"value"}' response.json

The CLI call triggers the function and returns a JSON response. You are billed only for the milliseconds your code actually runs — there is no charge when nothing is executing.

Best Practices

• Keep functions small and single-purpose so they start fast (cold starts matter).
• Set a sensible memory and timeout limit; excess memory is wasted spend.