BLT (Build and Launch Tool) provides an automation layer for testing, building, and launching Drupal 8 applications. It is the default recommended tool used by Acquia Professional Services.
We use BLT in Professional Services to sync databases, manage configurations, create artifacts for deployments, and tons of other things that -- most of the time -- save us time. If you have not tested it yet I’d recommend you to have a look: https://github.com/acquia/blt
DDEV, on the other hand, is a Docker-based, open source tool that helps you to quickly spin up a (local) environment in applications like Wordpress; Drupal 6, 7 and 8; Backdrop, and Typo3. Have a look at https://github.com/drud/ddev