I have no direct experience with scaling DynamoDB in production, so take this with a grain of salt. But it seems to me that the on-demand scaling mode in DynamoDB has gotten _really_ good the last couple of years.
For example, you used to have to manually set RCU/WCU to a high number when you expected a spike in traffic, since the ramp-up for on-demand scaling was pretty slow (could take up to 30 minutes). But these days, on-demand can handle spikes from 10s of requests a minute to 100s/1000s per second gracefully.
The downside of on-demand is the pricing - it's more expensive if you have continuous load. But it can easily become _much_ cheaper if you have naturally spiky load patterns.
> The downside of on-demand is the pricing - it's more expensive if you have continuous load.
True, although you don't have to make that choice permanently. You can switch from provisioned to on demand once every 24 hours.
And you can also set up application autoscaling in provisioned mode, which'll allow you to set parameters under which it'll scale your provisioned capacity up or down for you. This doesn't require any code and works pretty well if you can accept autoscaling adjustments being made in the timeframe of a minute or two.
We've some regular jobs that require scaling up dynamodb in advance few times per day, but then dynamo is only able to scale down 4x per day, so we're probably paying for over capacity unnecessarily (10x or more) for a couple hours a day
Now we just moved ondemand and let them handle it, works fine
For example, you used to have to manually set RCU/WCU to a high number when you expected a spike in traffic, since the ramp-up for on-demand scaling was pretty slow (could take up to 30 minutes). But these days, on-demand can handle spikes from 10s of requests a minute to 100s/1000s per second gracefully.
The downside of on-demand is the pricing - it's more expensive if you have continuous load. But it can easily become _much_ cheaper if you have naturally spiky load patterns.
Example: https://aws.amazon.com/blogs/database/running-spiky-workload...