Emoji suggestion: </strong>Slack might suggest emoji reactions to messages using the content and sentiment of the message, the historic usage of the emoji and the frequency of use of the emoji in the team in various contexts. For instance, if 🎉 is a common reaction to celebratory messages in a particular channel, we will suggest that users react to new, similarly positive messages with 🎉. To do this while protecting Customer Data, we might use an external model (not trained on Slack messages) to classify the sentiment of the message.