I like Rails, Bootstrap, React.js, postgres. I usually deploy to AWS.
Coffeescript, ClojureScript and jQuery are nice too.
I am lead developer of a B2B platform built on Rails that helps clients improve their customer service. We have about 1,000 clients and around 5,000 daily active users.
As a side project I built a machine-learning social media analytics tool using a mixed stack of Clojure, postgres, Redis, Ember.js and Rails.
I like giving back to open source projects and have contributed to yeSQL and Rails. I also maintain a Clojure library that wraps Java C3P0 database connection pooling.