For building and publishing, this is fantastic. One of the jobs in our current workflow boots up the circleci/android:api-29-node image in about four seconds with all the build tools we need. Chances are you can start with a prebuilt one. Overall, it’s great: Docker images are fast, portable, and cacheable. Since CircleCI 2.0, the recommended build environment for most projects is the Docker Executor. With a little tinkering, though, we can make it work in another environment! What Doesn’t Work The Android Emulator, unfortunately, doesn’t work in CircleCI’s conventional ( Docker-based) Android build environment.