I have worked in vROps which is web-based monitoring application for vCenter servers. The application is based on Java with ExtJS web UI. But I have also used NodeJS for some tasks with the grunt, gulp and also I have created some mockups with Angular. Here I get deeper in NodeJS and Angular and loved them. I wrote a tool with NodeJS which increased the performance of vROps UI for 6 times by bundling their scripts(tests were done for DSL network throttling).