AWS Lambda best practices

2 minute read

AWS Lambda has become one of the most popular serverless computing platforms in recent years. With Lambda, developers can easily run code in response to events without having to manage servers or infrastructure. However, like any technology, it’s important to follow best practices to ensure optimal performance, scalability, and security. In this blog post, we’ll discuss some of the best practices for using AWS Lambda.

Keep functions small and focused

AWS Lambda functions should be small and focused, with each function responsible for a single task. This makes it easier to manage and test your functions and also ensures that your code is reusable.

Use environment variables for configuration

It’s a best practice to use environment variables for configuration settings, such as database connection strings or API keys, rather than hardcoding them into your code. This makes it easier to manage and update your configuration settings without having to redeploy your code.

It is also good to avoid using external configuration sources such as AWS SSM (Systems Manager) Parameter Store to fetch configuration, even if only on cold start. This is for two main reasons; Parameter Store has quite tight service limits that can easily be reached on a fast scale up of lambda functions and fetching the parameters adds latency to the function execution duration.

Monitor function performance

Monitoring function performance is crucial to identifying and resolving issues before they impact your application. AWS Lambda provides built-in monitoring tools, such as Amazon CloudWatch, which can be used to track metrics, logs, and errors.

Use stateless functions

AWS Lambda functions should be stateless, meaning they don’t maintain any state between invocations. This ensures that your functions are scalable and can handle large volumes of requests.

Optimize memory allocation

AWS Lambda allocates memory to your functions based on the amount you specify. It’s important to allocate just enough memory to your functions to ensure optimal performance and reduce costs.

Secure your functions

Security is crucial for any application, and AWS Lambda is no exception. It’s important to follow best practices for securing your functions, such as using IAM roles and policies, encrypting data at rest and in transit, and implementing strict access controls.

Test thoroughly

Testing is essential for ensuring the reliability and functionality of your Lambda functions. AWS Lambda provides tools for automated testing, such as AWS CodePipeline and AWS CodeBuild, which can be used to test your functions before deploying them.