A Flipkart-style sale makes the bill jump fivefold. Bad news?
Not if cost per order stays flat. If it rises, something scales worse than linearly, such as a chatty service or an over-eager log level.
6%
of the photo app’s bill is compute
Take a photo app with 1M daily users: about $33k a month. Delivery is 48% and storage 25%. Bytes, not CPU.
Same bytes to S3. Why does one route cost $4,500?
Bytes are priced by where they go: $0.045 per GB through a NAT gateway, $0 through a gateway endpoint for S3.
Delivery is half the bill. What first?
Bad: A CDN in front
Still 225 TB a month: saves barely $1,070.
Good: Shrink bytes, then a CDN
WebP or AVIF at, say, 100 KB, not 150: saves $4,070.
Prime Video’s serverless stream monitor passed frames via S3. Why so costly?
The bill
Per-transition charges for every second of every stream, plus S3 calls for frames. One process on ECS cut cost over 90%.
Daily peaks, quiet nights. How much do you commit?
A committed hour is paid, used or not. Commit to the floor of 10: about $2,049 a month. Commit to the average of 20: $2,144, worse.
Every saving has a price
- Smaller images: transcode CPU, purges on delete
- Cold originals: retrieval fees if access changes
- Spot resizers: work re-queued on a two-minute warning
- Sampled logs: one successful request may be missing
The interview line
Cost is a requirement with a number. Divide the bill by business volume, cut the biggest line, and name the price.