Agree.<p>With AWS, once you start using multiple services (e.g. lambda, S3, dynamo db, etc), it&#x27;s difficult to estimate&#x2F;model the costs in advance.<p>First you have to estimate how many times your app is pulling down a file or hitting a given db table. But this is dependent on unpredictable user behavior. You don&#x27;t really know what users will do with your app until they actually do it.<p>Then, with e.g. Dynamo DB, you have to think about how many indexes you have on a table, and how often your app will query those vs how many times your app might do a full table scan. You have to allocate these specially defined AWS resource units. I don&#x27;t find it intuitive.<p>I wonder how many developers really know in advance what their app is going to cost per user.