Xoogler here (2014-2017). My team (part of Ads) used primarily Java, and we used the Eclipse, then we started switching the IntelliJ. Cider was used also a lot, but I've heard even back then some folks were free to use whatever they like - vi, emacs, you name it.
Yep, I made my own! (Xoogler 2017-2023) this is my noogler IDE story, one of my favorite, proudest hacks! I developed a fork of the IntelliJ IDE on my second week at google out of raw frustration over latency. At the time I was commuting 2-3hrs/day SF MTV on the gBus. Connectivity on the bus wasn't optimal, and there was high latency. Cider didn't have deep integration, and wasn't able to let me explore and understan…
Yeah, I was working out of the Sydney office. Almost everything was incredibly slow due to that latency, not just chromoting but also just accessing most sites through beyondcorp.