Type in a word and we'll check if it's a palindrome.
$ git clone https://github.com/namenotrequired/palindrome.git && cd palindrome
$ npm install
$ npm start
Now open localhost:3000 and see the magic in action!
I used Express because it's mature and I have experience with it. Plus express-generator allowed me to get started quickly on the application specific part.
I used jQuery for the front end because 1. it's what my last job used and 2. using a more advanced library like React or a complete framework like Meteor would be overkill for this simple job.