Alerting is one of the 5 A's of Cloud Security. There are countless metrics you can alert on in AWS, but the most important is the budget. Most developers I speak to don't equate spend to
billing
A collection of 3 posts
Serverless Cost Containment
Serverless soultions is can be incredibly cheap due to their event-based nature - if your system isn't working, you pay barely anything for it. But if you're not careful, serverless can still result in some nasty surprises when it comes to costs.
AWS Reserved Instances Cheatsheet
Reserved Instances (RIs) are a great way to save some money if you've got consistent AWS EC2 usage, without needing to make changes to your instances!