Most agents look impressive in a demo. Very few hold up in the real world. This masterclass goes deep on what it actually takes to build agents that are reliable, debuggable, and production-ready. Sierra engineers will unpack the core technical decisions behind high-quality agents—from system architecture and orchestration to evaluation, failure handling, and iteration in live environments. Expect concrete patterns, hard-won lessons, and a clear point of view on how great agent builders think, build, and ship at scale.