AWS Lambda Web Functions Introduced by Amazon Web Services

In announcements published by thenasguy.com and aws.amazon.com, Amazon Web Services has introduced AWS Lambda Web Functions, a new form factor designed to allow developers to run standard HTTP web applications on serverless infrastructure without rewriting code into event handlers.

Three Distinct Form Factors

According to the announcements, AWS Lambda now offers three distinct form factors built on the same Firecracker isolation technology, each tailored for a different programming model:

• Lambda Event Functions: The traditional Lambda functions utilizing an event-driven, single-concurrent handler model with wall-clock billing, designed for event processing, queue consumers, and invocations triggered by other services.
• Lambda Web Functions: A new HTTP-native form factor featuring multi-concurrent execution and active CPU billing, intended for web applications, API backends, and interactive HTTP workloads.
• Lambda MicroVMs: Isolated, stateful sandbox environments featuring customer-managed lifecycles for running untrusted or user-generated code.

Execution Model and Cost Structure

Lambda Web Functions allow developers to take standard port-listening servers built using frameworks such as Express, Hono, Fastify, Next.js, or any Node.js framework and deploy them with a single command without adapters or framework lock-in. Each execution environment is capable of handling up to 128 concurrent requests simultaneously, allowing incoming traffic bursts to share warm environments.

The billing model meters CPU time exclusively by the actual CPU used by the code—meaning time spent waiting on database queries or external API calls consumes minimal CPU—while memory is metered for the duration of the execution environment’s existence.

Deployment and Setup

Deploying a web application utilizes the AWS Command Line Interface with a single command (`aws lambda-web deploy –name my-web-app –code ./my-app`) requiring no prior resource setup. Applications utilize the `AWS_LAMBDA_HTTP_ENDPOINT` environment variable, which Lambda automatically configures to provide the host and port where the server must listen.