That being said, please don't think you need to know PHP to work at Automattic. I mean, it's useful, sure, but JS knowledge is huge as well, and we have some folks on our Data team that just do Python. Our Mobile team works pretty much purely in the languages for Android and iOS. Elasticsearch is something we also do huge amounts of work with (as @gibrown can testify)
If it's interesting to anyone, here's my resume as I submitted it with my application (with personal information redacted) (yes, I wrote it in markdown) -- https://gist.githubusercontent.com/georgestephanis/a5095ca4f...
- https://automattic.com/work-with-us/javascript-engineer/
- https://automattic.com/work-with-us/code-wrangler/
- https://automattic.com/work-with-us/mobile-developer/
- https://automattic.com/work-with-us/data-wrangler/
Lotsa fun problems to solve and 25% of the Web runs WordPress. Big impact at a moderately sized company.