Heroku provides you with all the tools you need to iterate quickly, and adopt the right technologies for your project.
Express is a fast, unopinionated, minimalist web framework for Node.js
Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.