Depends on many factors... It can vary from 5 to 30 minutes, from the moment someone presses "merge" on a pull request and the moment that change is live on a test environment. The average is probably around 10-15 minutes.
The builds for all services happen in parallel, so the longest one determines the total time. Big Scala services take much longer than small React frontends. We cache both Maven and NPM modules from previous builds.
Ideally, if the pull request only modified a React component and didn't touch any Scala file, no Scala build is triggered because Docker finds a cached layer and skips the "sbt compile" step. To be honest, we are still working to make sure this always happens, we still trigger unnecessary sbt compiles because the Docker cache is not used correctly.
The builds for all services happen in parallel, so the longest one determines the total time. Big Scala services take much longer than small React frontends. We cache both Maven and NPM modules from previous builds.
Ideally, if the pull request only modified a React component and didn't touch any Scala file, no Scala build is triggered because Docker finds a cached layer and skips the "sbt compile" step. To be honest, we are still working to make sure this always happens, we still trigger unnecessary sbt compiles because the Docker cache is not used correctly.