Simplicity of react is what made us choose it over angular. Angular may be the more complete solution but it surely comes at the cost of losing control as it wraps our apps as a framework, when we need a library for our ui.
The sacred history principle and the saner command interface is what made us go with mercurial rather than git. We mostly use centralized workflow and git seemed more focused on flows where thousands of people would contribute.
Buildbot gives us the power to create custom tasks in python. We simply need a tool to notify us of failed tests each time we push code and jenkins seemed as a overkill for that.
