S3

The Invisible Files on S3: Paying for Data You Can't See (Incomplete Multipart Uploads)

A large upload to S3 dies mid-transfer. The parts that already made it up don’t just vanish — they keep sitting there, billed every month, invisible to the console and to aws s3 ls. Hi everyone 👋 When an application uploads a large file to S3 using multipart upload and the connection drops partway through, the obvious assumption is: the upload failed, nothing happened, no harm done. That assumption is wrong in a way that quietly costs money.

Saturday, August 1, 2026 Read

Archiving Millions of Small Files to Glacier: When the 'Cheap Storage' Trick Backfires

S3 Glacier Deep Archive is famous for dirt-cheap long-term storage. Point a Lifecycle Rule at millions of tiny log files, though, and “cheap” can flip into “more expensive than doing nothing at all.” Hi everyone 👋 I once confidently set up an S3 Lifecycle Rule: “any object older than 30 days automatically transitions to Glacier Deep Archive.” Simple, standard cost-optimization advice. The catch: the bucket in question held millions of small log files, each only a few KB.

Friday, July 10, 2026 Read

The NAT Gateway 'Trick' That Was Actually Billing You for ECR, Not S3

A client’s NAT Gateway bill hit a record ~$3,000/month. VPC Flow Logs pointed straight at S3 — except the client swore they barely used S3. Here’s what was actually going on. Hi everyone 👋 A client came to us about a month after going live with a new system built by a different vendor — one they no longer had a maintenance contract with. Their first full invoice after launch showed a NAT Gateway bill at a record high, roughly $3,000/month. Standard architecture on their end: ECS services running in private subnets for security, NAT Gateway for outbound access. Textbook setup on paper — which made a bill that high, right out of the gate, more confusing, not less.

Thursday, June 18, 2026 Read