Cold start optimization for Java serverless functions

This repository contains a simple example of SOAP client on Lambda, optimized for faster startup. The client calls VIES webservice to validate EU VAT numbers

Prerequisites

• JDK 11+
• Docker
• AWS CDK installed and configured

How to build and install

You should run the following sequence of commands:

1. ./mvnw install to initialize dependencies
2. cdk bootstrap to initialize IaC environment
3. cdk deploy to deploy the infrastructure

Deploy will create the following resources:

• vies-proxy-11: Lambda running on Amazon Corretto 11 runtime, ready for SnapStart activation
• vies-proxy-19: Lambda running on a slim Amazon Corretto 19 runtime, using a custom Docker image
• an ECR repository to push vies-proxy-19 images
• vies-proxy-19-custom: Lambda running on a custom runtime based on Amazon Corretto 19

How to enable Lambda SnapStart

Lambda SnapStart can be enabled on the vies-proxy-11 function. To enable it, follow the official instructions