How Rex went from zero to enterprise ready in weeks

In January 2026, Merlin Kafka and Lewis Blackwood founded Rex, a company aiming to automate tedious and manual operational finance tasks for enterprise finance teams by using AI agents to handle accounts receivable and payable operations. Quickly gaining traction, Rex won first place in the Vercel AI Accelerator, securing investment from Vercel Ventures and demonstrating readiness to sell to large enterprises like Boeing and Walmart. The company prioritized robust security and authentication measures from the start, utilizing WorkOS for enterprise-grade authentication services such as SSO, SCIM provisioning, and passwordless authentication, which facilitated swift implementation and avoided procurement delays. The accelerator program not only provided networking opportunities and access to expert sessions but also aligned perfectly with Rex's existing tech stack, further enhancing their enterprise-readiness. As Rex emerges from stealth mode, they continue to expand their enterprise pipeline, leveraging the foundations built during the accelerator to meet the stringent security expectations of large organizations and differentiate themselves through a focus on good design and user experience.