If you need strong guarantees of isolation and if every user has their own dedicated installation. If you are a general service where isolation is enforced at t

If you need strong guarantees of isolation and if every user has their own dedicated installation. If you are a general service where isolation is enforced at the application level then just deploy straight away. Docker is useful when you don't want to care about the underlying operating system or you might be deploying on different operating systems etc. Also if you want to quickly switch providers (like going from Ubuntu 18.04 on digital ocean to Windows Server on Azure) since it's a self contained image. This self contained image is useful during development too. I can cleanly separate dependencies between applications and dev/test/prod. For example I develop a node app based on node 12 + pg 11 but I tinker with ghost too which requires node 10 + mysql. Having this in Docker keeps cruft and complexity off my macOS installation at the cost of space. Having multiple versions of a runtime/database etc can quickly become a nightmare to manage on local operating systems. Operationally if you can control deployment and you don't need many servers, deploying to the base operating system makes sense. Docker/Kubernetes shine when you have scale + need to provision many servers across different platform providers.