The openSUSE build service could build hundreds of packages in parallel but in practice serial package dependencies prevent that. So packages have to be built one after another which takes a rather long time and slows down development.

The diststats tools can simulate and visualize distribution rebuilds

It's also integrated in OBS, see for example Leap 15.0

In this graph one can see the time on the X axis and the number of packages on the Y axis. The three shades of blue indicate the package status. The brightest blue are packages building at the given point in time. The medium blue is packages that are ready to build but can't due to no free worker. The dark blue ones are packages that wait for depenencies to build. Ideally the graph should have a light blue line on the bottom that is exactly as high as the amount of workers available. Ie all workers busy all the time. In practice one can see that workers are not working fully to capacity. There are not enough parallel buildable packages due to dependencies.

The goal of this hack week project is to identify and fix bottlenecks in the build dependency graph. You can use the 'mkdiststats' and 'analyze' tools or by write your own tools that analyze the graph. Check the mkdiststats tool to find out how to get the information from obs.

Packages that have been identified as bottlenecks need to be analyzed and solution discussed and implemented. In case of Mesa, e.g. splitting out a Mesa-mini could be an option.