Cross-Region Egress: the ₹4L/mo invisible line on your AWS bill

Cross-Region Egress

The single most expensive accidental misuse of AWS we see in Indian mid-market accounts.

Pattern

Prod in ap-south-1. Data-lake S3 in us-east-1. Engineer ships a Glue job that SELECTs from the data-lake — every byte crosses the ocean at ₹7.5/GB egress.

Fix

• S3 replication to ap-south-1 for the hot prefixes, once.
• VPC Gateway Endpoint for S3 (free, eliminates NAT egress for the in-region reads).
• Athena/Glue queries pointed at the regional copy.

Payback in 6 weeks on a ₹4L/mo finding.