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- $60B in Receivables. Two Founders. One AI Ghost in the Machine.
$60B in Receivables. Two Founders. One AI Ghost in the Machine.
Rex replaces the manual order-to-cash operations that Fortune 100 companies have outsourced for decades. Won Vercel AI Accelerator. Now YC Summer 2026.
$60 billion. That is the size of the order-to-cash operations market — the manual work between "we closed the deal" and "the money is in the bank."
Two founders. Merlin Kafka (CPO of Sequence, a16z-backed) and Lewis Blackwood (founding engineer at Sequence). They spent years watching O2C run on armies of people in low-cost countries. Traditional automation fails because every customer has different context, different contracts, different exceptions.
Their solution: AI agents that run 24/7. Watching every invoice, every exception, every customer interaction. Manual cycles that took weeks now take hours. Half a billion dollars in receivables already managed.
Rex won the Vercel AI Accelerator — #1 out of 2,500 teams. Vivian Midha Shen is their YC partner. Summer 2026 batch.
The boring stuff is where AI wins hardest. Invoice disputes, cash application, payment follow-ups — no one builds demos for this. But $60 billion flows through it every year.