dazn-lambda-powertools VS jsii

I'm a big fan of TypeScript and in fact co-authored a book about it. I don't find myself using Java or Python much, so while I've been interested in Lambda Powertools, I never tried it out until now. Lambda Powertools TypeScript joins middy and DAZN Lambda Powertools in the Lambda tooling space for the Node.js runtime. Two things that differentiate Lambda Powertools TypeScript from comparable libraries are it is sponsored by AWS and it supports decorators.

The next natural step was to look at middleware such as Middy to decorate the main business logic, and allow these tasks to be defined once and used consistently. I remember listening to a Comic Relief talk about their Lambda wrapper back in 2019. Since then, I was introduced by Yan Cui to DAZN Lambda Powertools, which was the inspiration for this new project.

You might be interested in the logger/correlation ID features of https://github.com/getndazn/dazn-lambda-powertools - been super useful for us so far.

Nevertheless, log files are an important resource to debug problems and to get deeper insights into the behavior of a serverless system. Every logged detail might help to identify issues and to fix bugs and problems. Structured logging is important as log files can be analyzed much easier (e.g. with AWS CloudWatch Insights) which will save time and engineering costs. The dazn-lambda-powertools library provides a logger that supports structured logging for Node.js, the AWS Lambda Powertools offer the same for Python and Java.

What about jsii? The technology behind AWS sdks: https://aws.github.io/jsii/

Is Stainless similar, different?

The libraries for other supported languages of CDK are built as wrappers for underlying JS or maybe TS code via https://github.com/aws/jsii

So all the core CDK code is written first in JS/TS and then stubs for the other languages are added

Unfortunately this is often done without consideration for how the other supported langs actually work, and artefacts of e.g. JS lack of support for kwargs leak through

This is why e.g. the typing in CDK Python is completely broken - pretty much uniformly the concrete types like "Resource" don't implement their corresponding interface like "IResource" (to a type checker)

(There are many other typing niggles like this but that's the most egregious and pervasive one)

At the end of the day, having to explicitly cast concrete types as their interface to satisfy type checker is a minor annoyance, albeit a stupid one that could have been avoided with more care in the core library.

I could live with that, but I encountered so many bugs and issues trying to use CDK on current project that it's now much clearer to me why every company I worked at previously was using Terraform.

Pretty sure some of those issues are ultimately CloudFormation ones. The cumbersome CF > CDK JS > CDK Python stack is great for obfuscating errors and making debugging hard or impossible though.

Pulumi do something similar, albeit with Go as the core language and Terraform underneath. From what I've seen with a little use they have a much more successful result though, Pulumi Python was not a complete mess, and deploys faster and more reliable with better error feedback. I guess they just took more care to get it right.

Every version of the CDK uses an interop layer and runs on top of the Typescript version

https://github.com/aws/jsii

And as far as TF supports services before CFT. Guess which is easier for an AWS employee to do - getting the CF service team to support a new service or just contribute to Terraform’s open source project?

I know of at least one service where the service team introduced the needed APIs and then an employee of AWS wrote the TF provider and contributed to the project before AWS’s own internal team added it to CFT.

Source: former AWS ProServe employee

To "meet developers where they are" is a beautiful tenet of AWS, and of the CDK, and inspired us to create awesome technology such as JSII and constructs.

Yeah both CDKTF and Pulumi piggyback on JSII, a class translator that supports the languages you've mentioned, which was used as a building base for CDK.

The reason we chose to start with compilation to JavaScript and not some other popular cloud language is because JavaScript is currently one of the most used ones, and in addition, we are using JSII to write our SDK in Typescript and then export it for consumption in other languages, such as Go, Python, Java and others.

The CDKTF CLI is implemented in TypeScript. Providers and resources are implemented in TypeScript as well. jsii is used to compile the providers and resources to the supported languages.