I have only heard second hand, but internally Uber has always had a large litter of tools. There is always a little bit chaos edited out from what is presented

I have only heard second hand, but internally Uber has always had a large litter of tools. There is always a little bit chaos edited out from what is presented to the outside world. They run several container schedulers (YARN, Mesos, Myriad), they used to run several separate workflow orchestrators. The proliferation of tools allows to test out different ideas in production conditions which is not bad per se. But the duplication of efforts or variability has to come with some advantage to continue doing it. Infrastructure engineers wanting to reinvent the wheel can create a lot of technical debt fast, and leveraged one at that. This takes nothing away from the great work Uber has been doing in the area. They have definitely set a great direction for their platform.