The Story Behind Building the Slackbot 'Emoji Factory'

To help KakaoPay crew members communicate with personality on Slack, we developed the Slackbot 'Emoji Factory', which automatically generates emojis by combining desired effects and text.

Key features include custom emoji creation, which applies font size, color, and typeface along with animation effects such as rotating or enlarging text, and an electronic display board creation feature that can be used for announcements and more.

For image processing, we adopted Python's Pillow library, and used the Python Slack SDK to implement real-time, bidirectional communication based on WebSocket. We built the API with Flask and stored user tokens in MySQL, designing the system so that messages could be sent under the user's own name.

On the algorithm side, the optimal font size is calculated by incrementally reducing the text size, followed by center alignment within the background. For animated emojis, images are generated frame by frame and then combined into a GIF file.