Below are some valuable online references to CDK and its various components:

• API Reference
• https://docs.aws.amazon.com/cdk/api/latest
• Gitter Channel
• https://gitter.im/awslabs/aws-cdk
• Stack Overflow
• https://stackoverflow.com/questions/tagged/aws-cdk
• CDK GitHub Repository
• https://github.com/awslabs/aws-cdk
• CDK at re:Invent 2018
• https://www.youtube.com/watch?v=Lh-kVC2r2AU