When a private EC2 needs to talk to an AWS service like S3, the normal path looks like this:
Private EC2 → NAT Gateway → Internet → S3
This means your traffic is going out to the public internet just to reach another AWS service. That's slow, costs money (NAT Gateway charges), and is less secure.
dont confuse that isnt service are not in same VPC because services like s3 are on default VPC so needed internet to connect
VPC Endpoint gives you a direct private path:
Private EC2 → VPC Endpoint → S3
Traffic never leaves AWS's private network. No NAT Gateway, no Internet Gateway, no internet.
| Without Endpoint | With Endpoint | |
|---|---|---|
| Path | Through internet | Private AWS network |
| Cost | NAT Gateway charges | Free (Gateway) or cheap (Interface) |
| Security | Traffic on public internet | Traffic stays inside AWS |
| Speed | Slower | Faster |
Think of them as two different private doors to reach AWS services.
A Gateway Endpoint works by adding a special route in your route table that points directly to S3 or DynamoDB (only for these 2 services).
Private EC2 → Route Table → Gateway Endpoint → S3 or DynamoDB
Key facts: