I personally am using the JVM as my platform, grails as my 'backend' framework, ember as my front end and postgres (or should I say hibernate?) in the database realm.
I feel like getting to know other devs stacks helped me realize what is really important for a modern web app development.
So what is your stack?
For the frontend, I am writing a routable, cached SPA in React and d3, orchestrated with Flocks, stored in S3 and fronted with CloudFront, generated by Node, backed with MySQL (because it has semi-mature clustering.)
For the backend, I use a custom Erlang stack built on htstub and emysql.
The build process is orchestrated with gulp, uses eslint, vows, karma, and jsverify for testing, travis ci for CI/CD, and deploys automatically on full test passing. (I have extensive test coverage.)
I can use remarkably few tools to get the results I want. I am happy with the stack.
I have an alternative approach to handling multiple interfaces, as a replacement for responsive. I don't use media queries to do that. Instead I have a top level React layout control, and which top level control is invoked is based on the client. The same goal is suited, but it isn't jury rigged through CSS.
I'm more interested in building a very efficient and reliable service and solving challenging problems than using trendy technologies.