Managing per deployment stage (e.g. prod, dev) configuration using CDK?

We're migrating from Serverless Framework (SF) to CDK and I'm wondering how to best manage per deployment stage (e.g. prod, dev) configuration using CDK. IN SF we had a YAML block like this:

  prod:
    alertsEmail: alerts@ourdomain.com
    captchaSecretId: prod/Backend/CaptchaSecretId
    enableAlarms: true
    enableDashboards: true

  dev:
    alertsEmail: dev-alerts@ourdomain.com
    captchaSecretId: prod/Backend/CaptchaSecretId
    enableAlarms: false
    enableDashboards: false

  default:
    # ...

("default" was used for all other stacks, like the per-developer sandbox stacks.)

These configuration variables then affect how we set up our CloudFormation (CF) resources. For example, if enableAlarms is true we'd add a bunch of Alarm resources.

• What's the recommended way to store per deployment stage configuration?
• How do we best specify which environment we're in when deploying? Using SF we'd do serverless deploy --stage=prod and the configuration got pick using the --stage command line flag.