[serbancon]

Yes, you are correct - SourceFS also caches and replays build steps in a generic way. It works surprisingly well, to the point where it’s hard to believe until you actually see it in action (here is a short demo video, but it probably isn't the best way to showcase it: https://youtu.be/NwBGY9ZhuWc?t=76 ).

We intentionally kept the blog post light on implementation details - partly to make it accessible to a broader audience, and partly because we will be posting gradually some more details. Sounds like build caching/replay is high on the desired blogpost list - ack :-).

The build-system integration used here was a one-line change in the Android build tree. That said, you’re right - deeper integration with the build system could push the numbers even further, and that’s something we’re actively exploring.