How Six AWS Engineers Rebuilt Bedrock to Challenge Microsoft

In early 2025, things were tense inside Amazon’s cloud unit. Bedrock, a new service designed to run AI models, was proving buggy. Customers were getting error messages repeatedly and sometimes waiting weeks for the computing capacity they needed, according to people with knowledge of the customer issues.

As these problems surged, a senior engineering leader, Anthony Liguori, led a team that came up with a plan for a revamped version of Bedrock—known as Project Mantle—designed to fix the throttling and error messages and enable the service to scale to serve larger numbers of users, said two of the people with direct knowledge of the situation. Liguori worked with five other senior engineers to build Mantle using AWS’ in-house AI coding tool, Kiro.