Andres Moreno Profile Pictrue

Andres Moreno

I'm Andres Moreno, Principal Software Engineer at Tyler Technologies. I focus on serverless techonology in AWS

Using YAML anchors and aliases in a SAM template

Learn how you can setup your SAM template to reuse common pieces of config by using anchors and aliases without introducing any problems.

5-Minute Read

Image of a diagram in excalibur showing a Step Function calling a Lambda Function and the Lambda Function calling out to the Internet with the Lambda Function crossed out

Last month I wrote a post about getting rid of Lambda Layers by using ESBuild. What I quickly learned is that the Metadata attribute has to be copied and pasted for EVERY Lambda function in your stack. I tried using the Global section in the SAM template and it turns out it’s not supported. I started thinking about how I could reuse the same configuration across my template and found that YAML already has a functionality that does this called YAML Anchors and Aliases. In this post I will…

Drop the layers, bundle up with ESBuild instead

Learn how you can structure your serverless projects to share code between Lambda Functions using ESBuild instead of Lambda Layers.

5-Minute Read

Image of a person removing a jacket into a stack of other jackets the person has already removed

I’ve seen a lot of posts around the problems that Lambda Layers bring. A very good one is called You shouldn’t use Lambda Layers by AJ Stuyvenberg. In this post AJ explains the myths and cons of using Lambda Layers. What is not easy to find is examples on how to actually get rid of Lambda Layers by using a bundler. In this post we will go through a structure and configuration that allows us to remove Layers by using ESBuild to bundle the dependencies and shared code for our…

How to update Lambda Functions from Common JS to ECMAScript

Follow these 3 steps to update your Common JS Lambda Functions to ECMAScript Modules (ESM)

2-Minute Read

Cartoon image of a laptop with gears and a person with a big wrench

Version 5.0.0 of the @middy/core package no longer supports Common JS in favor of ECMAScript Modules (ESM). ESM improves performance by 2X as mentioned in this post. Seeing this change prompted me to investigate what needs to be updated to get Lambda functions to be ESM to not fall behind on my dependency versions. In this post, we’ll go through the 3 steps needed to go from Common JS to ESM.

Speed up new serverless application development with customized SAM templates

Learn how you can use custom templates with SAM to speed up initial application setup.

3-Minute Read


As you start setting patterns and best practices within your projects at some point you will want to share these to simplify the lives of other developers.
SAM allows you to initialize projects by using the init command and selecting a template for your project. SAM has built-in templates to generate simple Hello-World starter projects (you can find the list of templates here). These will help you get started and get familiar with how to structure your serverless applications but as your…

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