That is genuinely great, however it's very not common.
I think the main challenge of not using those technologies might affect talents not joining companies like yours.
It is very common. The number of virtual server instances running far outnumbers the number of k8s deployments. I don’t have a company, I freelance, doing lots of system admin. I have yet to see k8s in a production environment. I do see Docker now and then, mainly for development. As far as I can tell bare virtual servers continue to dominate, with k8s mainly used by startups.
It's a shame that app engine is still running on go 1.4.2,
I would have understand if it was using 1.5 (since 1.6 is still quite new) but 1.4.2 still uses the old and slow GC.
And now this...
If you pay attention to where AppEngine is getting love these days, it's moving towards Google-accessing libraries on VMs, and becoming relatively language-agnostic. The just released Node.js libs, and other languages are coming.