A job that took five NTT DATA engineers three days now takes about 30 minutes.
NTT DATA is one of the world's largest IT services companies, the kind of firm a bank, insurer, or manufacturer hires to build and run its software. It handed OpenAI's Codex, a tool that writes and tests code, to 9,000 of its own staff, and reported that single result. The two companies signed a global partnership in April 2025 built around putting these tools inside NTT's workforce first.
For a services business, that number changes the arithmetic. Firms like this one grew the same way for decades: win more work, hire more people, bill more hours. The hours were the product. When one engineer with an AI tool does in half an hour what five did in three days, the old link between more revenue and more staff comes apart.
The work is spreading past engineers, too. OpenAI's own study of Codex, published this year, found the tool moving into finance and legal teams, where people who never learned to code use it to pull data and draft documents.
For the company on the other side of the invoice, the arithmetic runs in reverse: the firm you pay by the project or by the head is learning to produce more without adding people, and work that once billed for five engineers over three days need not cost what it did.