What is the daily volume of Slack messages sent?

This question may seem unusual to many, as it doesn't appear to be a typical interview question. However, employers often pose such queries to assess your estimation skills and critical thinking. They are interested in how you apply your knowledge to make informed guesses and how you tackle problems when you have little or no direct information. While you likely do not know the exact number of Slack messages sent daily, and it's not expected that you do, what is important is your capacity to arrive at a sensible estimate in a logical and organized manner.

To calculate the daily volume of Slack messages, I would begin by looking at the number of employees in organizations that utilize Slack. Let's say there are approximately 1 million companies worldwide using Slack, with an average team size of 100, resulting in around 100 million users. Additionally, if each user sends roughly 50 messages daily, including both direct and channel messages, we arrive at an estimated total of about 5 billion Slack messages sent each day. While these figures are merely approximations, the aim is to illustrate my reasoning in addressing this issue.

Estimating figures in this manner requires making several educated assumptions. For instance, based on some information I came across, there are approximately 750,000 organizations utilizing Slack. If we assume an average of 200 employees per organization, that results in around 150 million Slack users. Considering that each user sends about 30 messages daily, both personal and group messages combined, we would be looking at roughly 4.5 billion messages sent each day. While this is a broad estimate, the key point is that the reasoning behind the estimation is what truly matters.