One of the most difficult things with DocumentDB is figuring out how many Request Units per Second (RUs/s) you need to run your application day to day but also during usage spikes. When you get this wrong, the DocumentDB client will throw exceptions, which is a terrible usage model.
If my application has particular times of the day where it would use a higher number of Request Units per Second (RUs/s), then how do I handle this in DocumentDB? I don't want to set a really high RUs/s all day because I would get charged accordingly. I also don't want to have to log into the Azure portal each time.
You could create a job on Azure that scales up the throughput of your collections only at the time of day that you need it and then scale down afterward.
If you are targeting DocumentDB from .NET, this Azure article has example code that shows how to change the throughput using the .NET SDK.
The specific (C# .NET) code referenced in the article looks like this:
I assume that the DocumentDB SDK for other languages would have the same feature.
Additionally, from an Azure article found here you can use PowerShell to change the service level.