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.
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.