AWS Serverless Application Model (SAM) CLI now supports local testing of AWS Cloud Development Kit (CDK), announcement here
about the general availability.
DynamoDB which is also known for the PartiQL support now can return the throughput capacity consumed by PartiQL APIs which can help you optimize your queries and throughput costs, you can read more about it here
If your Lambda functions have event sources such as Amazon MSK, Apache Kafka, Amazon MQ then you may want to look into announcement about Max Batching Window which helps you fine tune your Lambda invocation helping you to optimize on your costs, read more about it here
And after a long wait, a good news to anyone who uses S3 Web console as AWS have answered the request for generating presigned URLs from the console.