That’s a really good question. You know how we always said there’s hope that Apple won’t ditch the Mac since they themselves couldn’t stand to use Windows or Linux for their workstations...
I have no knowledge of their internal setup, but I suspect they have a big room full of racked ESX servers (non-Apple hardware) running builds on macOS VMs. And probably a ton of networked iPhone motherboards running automated tests.
I just wish they would make that kind of setup (macOS VMs on non-Apple hardware) legal for other developers.
My understanding is that internally when they have tasks that their own hardware isn't appropriate for they use a combination of Linux and macOS running on commodity PC hardware. They have an internal version of macOS for the commodity PCs. The person who told me hinted they got machines from a big name vendor like Dell or HP. I was informed of this in a discussion about AR and VR. Basically we all asked how Apple even did work on this internally when their own machines clearly had some issues with that sort of workload. This was like six months ago and related to speculation about showing the new Mac Pro at WWDC 2018, which didn't end up happening.
Interesting. I wished Apple had a Mac Pro that is basically the old Cheese Grater, and rack based in the size of 3U or 4U. It should aim to hit both market with a single design. I mean even if they do it for internal usage, along with other niche for Server and Pro uses would be enough to sustain the business.
When I worked as a consultant for Apple Retail Software Engineering, we did have huge clusters of machines running VMware — on the biggest, beefiest, Xserve hardware that could be bought. Maxed out on RAM, CPU, and everything else that could be crammed into those boxes.
I was told that the entire final run of hardware was reserved for Apple internal use.
Our Jenkins CI/CD server was just a VM on the cluster, and ran Xcode to do the iOS and MacOS X builds on one set of slaves, and the Linux back-end server software on another slave.
> I was told that the entire final run of hardware was reserved for Apple internal use.
I get the sense that Apple's strict devotion to its product line is (to put it nicely) creating a discontinuity between their own practices and what they offer to others. It makes me think Apple needs a separate company or brand to offer practical utilities (and perhaps consulting) to companies wishing to deploy Apple software -- things like licenses to use macOS on non-Apple hardware (like a Dell EMC VxRack SDDC[0]), productizing some of their own IT solutions, special iPhones with a 1Gb RJ45 port attached for automated testing, and even "catch the vision"-style marketing to promote their idea of a data/compute center that integrates macOS and other Apple technologies.
I have no knowledge of their internal setup, but I suspect they have a big room full of racked ESX servers (non-Apple hardware) running builds on macOS VMs. And probably a ton of networked iPhone motherboards running automated tests.
I just wish they would make that kind of setup (macOS VMs on non-Apple hardware) legal for other developers.