Aurora serverless is an option that allows you to automatically scale the size of your database up and down depending on usage. If your app is not in use constantly, the instance will be shut down to save money, and then it will be quickly spun back up in response to activity. While not a good choice for applications that see 24/7 usage, it is definitely an option to consider for departmental line-of-business databases that only see use during business hours.

Another interesting feature of Aurora is the ability to create custom endpoints that point to a subset of read replicas. This gives you the ability to create replicas with configurations tuned toward specific workloads and direct those queries at just those replicas.