Cowboy is a small, fast, modular HTTP server written in Erlang.
Express is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Heroku is a cloud platform as a service (PaaS) supporting several programming languages.
Mailchimp is a marketing automation platform and email marketing service.
Mapbox GL JS is a JavaScript library that uses WebGL to render interactive maps from vector tiles and Mapbox styles.