The Service Manual

AWS, one service at a time: where each one came from, how it's actually built, where it creaks, and why the bill looks the way it does. Part of Under the Hood.

Under the Hood · The Service Manual

How S3 Actually Works

S3 stores more than 500 trillion objects and answers over 200 million requests a second, on an API that has barely changed in twenty years. Between your PUT and the disk sit erasure codes, a formally checked storage node, and one of the largest distributed systems ever run.

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How IAM Actually Works

Every AWS API call is an HTTPS request carrying an HMAC signature, evaluated against a stack of JSON documents in a few milliseconds. IAM does this over a billion times a second, and the answer it gives decides everything else that happens in the cloud.

Coming soon