The FinOps Guide to Managing NAT Gateway Spend

In FinOps, we talk a lot about Compute (EC2/Kubernetes). We rarely talk about Networking until the bill arrives. Here is how to bring FinOps discipline to your VPC network.

1. Tagging Strategy

You cannot optimize what you do not own. Tag every NAT Gateway with:

• Environment: (Prod/Stage)
• CostCenter: (Shared Infrastructure)
• Owner: (Platform Team)

2. Unit Economics

Stop looking at “Total Spend.” Look at “Cost per GB.”

• Metric: Total NAT Cost / Total Data Processed.
• Goal: Drive this number down by using Endpoints (S3/DynamoDB) to bypass the NAT.

3. Anomaly Detection

Set a CloudWatch Alarm on NatGateway-Bytes. If traffic spikes > 50% week-over-week, alert the Platform Team. It usually means a bad code deploy is re-downloading a massive dependency on every loop.

4. The Policy

“No NAT Gateways in Sandbox Accounts.” Enforce this via Service Control Policies (SCPs). Developers in sandbox accounts should use Public Subnets or NAT Instances to save money.

Summary

Treat networking like a utility. Monitor the usage, detect leaks, and enforce efficiency.

[!TIP] Start with a baseline. Use our Pricing Calculator to establish what your “Should Cost” model looks like, then compare it to your actual bill.