We have Apex code with callouts that use hardcoded credentials. Our organization wants to replace the hardcoded credentials with a secure key store that we can retrieve the credentials from. We are familiar with AWS Secrets Manager / AWS Key Management Service and would like to use something similar from within Salesforce.
Is there anything similar to AWS Secrets Manager within Salesforce? It doesn't seem like it.
We've looked at Named Credentials, but they don't handle all our use cases. Protected Custom Settings or Protected Custom Metadata seem like a possible solution, but we really don't want to take on the overhead of using managed packages.
What's the best solution for a development team that is used to working with AWS Secrets Manager and similar type key storage services?