Some of my first experiments in the world of building a slack bot was to develop a basic Slash command using the WordPress REST API as a backend. If you or your team are the only users that intend to use it, you can just set it up as a simple integration. However if you wish to distribute it for others to use you can package it into a Slack bot.
An advantage of building a Slack bot versus a slash command is the additional features of the Slack API you can leverage – in this example, the RTM (Real Time Messaging) API. That allows you to listen and respond to messages in real-time. I started out building this layer as a WordPress plugin so anyone could install the plugin and build a WP powered bot. Not only was that out of scope for a fun side project, Node is really the right tool for the job – asynchronous, great packages for the Slack API, easy to deploy and scale (because who doesn’t wan’t a Kramer bot).