It covers more than 200 AWS services and was written entirely by agents. The most useful part of the launch is a story Swami Sivasubramanian tells in the announcement.
About 20 years ago, Sivasubramanian helped build the replication engine inside Alf, a Paxos-based lock service that still powers AWS systems such as S3 and DynamoDB. The first build took about four months.
When he later asked Kiro, AWS's agentic coding tool, to rebuild it, he supervised the agent for four nights before he saw the problem: The agent had no way to check its own results. Once it had a spec and a test environment, the rebuild took about two hours.
Four nights became two hours because the feedback loop changed. "An agent is only as good as its verification loop, and a verification loop is only as good as what it runs against."
As Sivasubramanian puts it, distributed systems are hard to test. That matches what I see across teams running coding agents on production systems.
