I've seen some venting in the comments here about Gradle and general build times. So I thought I would mention Buck[0] as an alternative build system. Vine as a great article up about how they sped up their build when switching from Gradle to Buck[1] - a large part of that was due to Buck's exopackage[2] feature.

For the curious, Google has a system like Buck - Bazel[3]. From what I know it served as the inspiration for Buck, but I could be wrong.

[0] https://buckbuild.com/

[1] http://engineering.vine.co/post/117873038742/reducing-build-...

[2] https://buckbuild.com/article/exopackage.html

[3] http://bazel.io/