Hosted Agents

It covers the infrastructure patterns that matter: pre-warming sandboxes so users don't wait, snapshot/restore for fast follow-ups, warm pools for high-traffic repos, and the git config gotchas when agents commit code. The real insight here is treating startup latency as the primary enemy, which means doing everything possible at image build time and parallelizing sync with user typing. Also walks through self-spawning agents where one agent can kick off sub-sessions for parallel work, which frontier models can actually handle now if you design the primitives right.