How Fyxer built an AI executive assistant people trust

For many professionals, work means keeping track of conversations and commitments across inboxes, meetings, messages, and apps. Without rock-solid context, those commitments can fall through the cracks, damaging projects and relationships.

Fyxer built an AI executive assistant that follows the thread as work moves across tools. It combines the latest OpenAI models with more than 500,000 hours of executive assistant workflows, dividing the work among dozens of specialized models that improve through real user feedback.

Email is one of the clearest places to see it in action. Two people can receive the same email and need completely different replies depending on the relationship, what has happened before, and what each person is trying to get done. That makes a seemingly simple task deceptively hard for AI.

“There’s something called Moravec’s paradox,” explains Fyxer Co-founder Archie Hollingsworth. “Things that humans find easy are hard for computers, and things that computers find easy are hard for humans.” Fyxer handles that complexity by learning how each user works, so it can respond like an assistant who already knows what matters.

Frontier OpenAI models support key parts of the experience, from understanding the email and finding the right context to generating the draft. Fyxer chose OpenAI because its models performed best on Fyxer’s internal benchmarks, offered strong fine-tuning capabilities for subjective tasks like tone and intent, and provided hands-on engineering support through whiteboarding sessions and technical collaboration.

“We chose OpenAI because they have the best models, and they’ve given us real access and a close working relationship. I can drop a question in Slack and get an answer quickly, and when we face a problem, the team comes to our office and works through it with us. They show up.”

—Archie Hollingsworth, Co-founder, Fyxer

Fyxer’s approach offers three lessons for founders building highly contextual AI products: