$187 and 16 Hours: My First Million-Token Session

Two things landed in the same week: the 1 million token context window and the Claude Agentic Teams beta. One gave me room to think. The other gave me a way to parallelize. I did what any reasonable engineer would do: I immediately tried to break both with something too ambitious. The plan: build a complete cashback campaign web application — backend, frontend, full test suite, containerized deployment — in a single session. One orchestrator. Eight specialized agents spawned as a team. Don't stop until it's live. What actually happened is more interesting than either the successes or the failures on their own. The Setup The Agentic Teams feature was the key enabler. Instead of one agent doing everything sequentially, I had an orchestrator that spawned specialized subagents — each with its own fresh context window, each focused on one domain: Backend implementer — Spring Boot service, API endpoints, business logic Frontend implementer — React SPA wired to the backend QA reviewer — runni