My current thought process is you use a relational db like postgres with json support to go from hobby &#x2F; early startup to traction where you would need to start being concerned with scaling. At that point you switch to kafka or related hosted tools.<p>As far the data you put into the stream, I would think it could be everything if you treated all data as immutable even admin actions? Only thing that seems up in the air is transactions.<p>That is as far as I got though. I don&#x27;t work with a company that has that kind of scale to use this, but I&#x27;d like to start working with it.