Thoughtworks names the tax an orchestrator pays itself

Editor's note, August 3: the publisher has since returned this article to draft and added a request not to share it. We removed the link. The description below records what was publicly available when this edition was assembled.

Garg argues that subagents are routinely justified by the wrong thing. "Every token in the orchestrator's context is competing for its attention, and the real value of a subagent is what it keeps out of that context, not how fast it runs." He reports a first-party incident: four subagents launched in one wave against a .NET response-pipeline refactor, three completing in roughly 12, 5.5 and 7 minutes, about 12 minutes wall clock against roughly 25 serialized. The speedup was real and beside the point. Two coinages come out of it, the orchestrator's tax and cognitive locality, the latter defined as "Tasks that need the same mental model should usually stay together." Martin Fowler edited and amplified the piece, and it explicitly extends his and Birgitta Böckeler's harness taxonomy with a fourth kind: the orchestration process itself.

Why it matters: Most decomposition advice in circulation optimizes for parallelism. This inverts the objective to context hygiene, which is a different and usually better target, and it gives you a name for the failure you have probably already hit: splitting work that needed one mental model, then paying three agents to rebuild it.