Fyxer leverages OpenAI models, fine‑tuning, memory, and real user feedback to organize inboxes and draft emails in each user’s voice. The system breaks email into 30‑50 specialized models, each handling narrow tasks like reply classification, intent analysis, and tone‑matching, rather than relying on a single text‑generation model. By training on over 500,000 hours of human executive assistant workflows, Fyxer captures how real assistants prioritize context, decide what to remember, and generate personalized responses.

OpenAI’s frontier models power key stages—from digesting emails to re‑ranking context and generating drafts. Co‑founder Archie Hollingsworth highlights OpenAI’s superior performance, fine‑tuning flexibility, and hands‑on engineering support. The approach underscores three lessons for founders: decompose complex tasks into smaller models, train on authentic assistant workflows, and integrate memory to maintain relevant context across conversations.