Use AWS Budgets to track project infra costs

Since we've been extensively using the Team tag for most of our AWS resources in the ECI account, it's quite easy to assess our project costs using this Cost Allocation tag. AWS has a budgets feature that lets us set a budget on a set of resources (identified by tags) and get notified monthly/daily/quarterly etc. if our actual or forecasted AWS costs exceed this budget. Here's a sample budget that we created for the reconciliation tools project identified by the tag Team: ecircon - you can note that this is a monthly budget on unblended costs, set to notify the team email if our forecasted costs exceed 90% of our budget!

This budget feature allows you to customize your budgets based on:

Here's a sample PR to get this started using Terraform.

FAQ:

Q: What should my project's budget $ be?
A: This is up to your team, an easy way to start would be to use the cost estimate you created during project design phase and then tweak based on changing requirements. You can also refer to this 2021 Corptech infra estimation sheet.

Q: Should I use unblended / blended / amortized costs for aggregation?
A: This depends on how you created your estimate. You can read about these cost types here.