What is the best way to build a directory site with voting functionality similar to product hunt?

Telescope is a perfect tool for those that want to get something up quickly with little to no engineering work. Like Product Hunt, it has an email-centric approach to manage a daily or weekly newsletter of content submitted and curated by the community.

+1. Telescope is your best option. Doesn't tick off all of your requirements, but gets very close. If you're interested in exactly what we use to build PH. We keep our stackshare up-to-date here: https://stackshare.io/product-hu... Also - we try to share as much as possible through open source. Can see here: https://github.com/producthunt. But for the most part, everything is custom built.

You should definitely build it on the Telescope (Meteor.JS)

You can create different boards and in each board, users can create posts, upvote/downvote, add images, discuss by leaving a comment. You can also embed the boards as a widget anywhere.

If you want to get something built in a day that functions similar to Product Hunt, Bubble should be your product of choice. With Bubble you can drag and drop elements to the page, position objects how you want (avoiding all that nasty css), and can even build a responsive site.

This is a WordPress theme to create a PH-style site you may find easy to use

Helprace has everything you require. It has posting, commenting, voting (multiple increments), category management, following, email notifications, embeddable media, moderation (pre and post) and agent collision detection. It also has SSO, API, Webhooks and the option to posting without signup.