I worked with the article's author. The build system mentioned was not sbt but a custom, in house, thing that was really just a medium sized Scala program that

I worked with the article's author. The build system mentioned was not sbt but a custom, in house, thing that was really just a medium sized Scala program that was used to build a number of large C++ programs, libraries and some other things). There were no build scripts but just raw Scala code fragments distributed over the hundreds of directories involved. Overall it was a pretty awful system but it would have been awful in any language given the approach taken (I hated it with a passion).