We've been managing AWS infrastructure for Australian businesses since 2002. The same cost mistakes keep showing up on invoices.

Here are the three most common — and what to do about them.

1. Oversized EC2 instances that were "set and forgotten"

A team provisions a large instance for a launch, traffic normalises, nobody downsizes. At scale, this is thousands per month. Fix: quarterly right-sizing reviews using AWS Compute Optimizer.

2. NAT Gateway charges from unexpected data transfer

Billed per GB and easy to miss. We've seen clients burning $3,000–$8,000/month on data transfer they didn't know existed — often from logging pipelines routing through NAT unnecessarily. A VPC flow log analysis exposes this in minutes.

3. Unused Elastic IPs and unattached EBS volumes

Elastic IPs not attached to running instances cost $3.65/month each. Doesn't sound like much until you have 40 from old deployments. Unattached EBS volumes are the same story. A monthly cleanup sweep eliminates both.

None of these require architectural changes. They're operational hygiene — and they compound into serious savings over 12 months.

If you want a no-cost AWS cost review, reach out. We'll show you exactly where the waste is.

— Habitat3 | AWS Partner, Sydney