Asana says OpenAI Codex completed an engineering migration it had expected to take at least five years in about two weeks, for roughly $12,000 in model and infrastructure costs. The project: removing Enzyme, an outdated testing system that had become a blocker to upgrading Asana’s frontend stack. The company’s previous staffing plan estimated the migration would cost roughly $6 million. Instead, Asana gave Codex a prompt only five sentences long. Up to four coding agents worked in parallel, each operating in a separate copy of the codebase. A human engineer checked progress roughly twice per day and reviewed every proposed change before approval. Asana says simpler instructions actually worked better than a more elaborate setup. The result: Expected timeline: ≥5 years Actual: 1.5 weeks of engineering effort across 2 calendar weeks Previous staffing estimate: ~$6M Model + infrastructure cost: ~$12K There are probably THOUSANDS of old migrations and rewrites sitting inside companies because nobody can justify spending years on them. If agents make those projects cheap enough to attempt the engineering backlog itself starts changing.