The intended audience for these demonstrations includes people who are not software developers. However, those conducting demonstrations based on these demo scripts and videos, and those viewing or following them, might be curious about further details on the CDK.
For such curious people, the AWS CDK Workshop might be of interest.
Developers have their choice of programming language used to leverage the power of the CDK. At the time of this writing, the CDK workshop was available in TypeScript, Python, .NET, Java, and Go.
Visit the AWS CDK Workshop at https://cdkworkshop.com.
Then come back here for more demos. Doing the CDK Workshop is not required to be able to follow the demonstrations here.