Which service would a data engineer use to encrypt data in their data lake?

Using AWS Key Management Service (AWS KMS) for encrypting data in a data lake is a suitable choice because AWS KMS is specifically designed for the management of cryptographic keys and provides a robust way to create and control keys used for data encryption.

In the context of a data lake, which often comprises massive amounts of collect data, KMS enables data engineers to ensure data confidentiality and integrity by encrypting the data at rest and in transit. AWS KMS allows users to define permissions and policies, ensuring that only authorized entities can manage or access the encryption keys. This level of control and security is crucial when dealing with sensitive or critical data stored within a data lake environment.

Other services mentioned, such as AWS Secrets Manager, are focused on managing secrets and sensitive configuration information rather than encrypting large datasets. AWS CloudTrail is primarily used for logging and monitoring AWS account activity, while AWS IAM (Identity and Access Management) deals with user permissions and identity management, but does not provide encryption capabilities itself. Thus, AWS KMS is the most appropriate tool for the encryption needs of a data engineer managing a data lake.