After running Bun on Lambda for 60 days, we discovered it's 3x faster than Node.js 22. However, the transition wasn't without its surprises. Here's what broke and what didn't. We're sharing our findings to help you decide if Bun is ready for your production environment. Introduction to Bun and Lambda Bun is a modern JavaScript runtime that promises significant performance gains over traditional Node.js. To test its claims, we set up a simple Lambda function using the @aws-sdk/client-lambda package: import { LambdaClient , InvokeCommand } from ' @aws-sdk/client-lambda ' ; const lambdaClient = new LambdaClient ({ region : ' us-east-1 ' }); const params = { FunctionName : ' bun-lambda-test ' , InvocationType : ' RequestResponse ' , Payload : JSON . stringify ({ message : ' Hello from Bun! ' }), }; const invokeLambda = async () => { try { const data = await lambdaClient . send ( new InvokeCommand ( params )); console . log ( data . Payload ); } catch ( err ) { console .…