Fyxer Launches AI Executive Assistant Built with OpenAI Models

Fyxer, a startup based in Europe and the UK, has launched an AI executive assistant that uses OpenAI models and over 500,000 hours of executive assistant workflows to draft personalized replies. The assistant, which combines the latest OpenAI models with extensive real-world data, aims to provide a more human-like experience by understanding the nuances of professional communication.

According to Fyxer Co-founder Archie Hollingsworth, the assistant addresses Moravec's paradox, where tasks that seem simple to humans are complex for AI. Fyxer's system breaks down email tasks into smaller components and trains on how great assistants actually work, improving through real user feedback.

The startup spent years operating a human-powered executive assistant service, accumulating a dataset of over 500,000 hours of annotated executive workflows. This dataset captures the small judgments behind a good response, such as when to answer quickly or which earlier conversation matters.

Fyxer uses supervised fine-tuning and Low-Rank Adaptation (LoRA) to create task-specific model variants while controlling training costs. The team evaluates models on validation sets built around email tasks, including drafting, classification, and prioritization, weighing accuracy alongside response time and cost.

Once deployed, Fyxer's system continues to improve through real user feedback. When users edit drafts before sending them, the differences are used to train the model via Direct Preference Optimization (DPO). The system performs A/B tests for each drafting change, deploying new versions only when they produce statistically significant improvements.

Today, 53% of Fyxer’s AI-generated drafts are accepted as written, indicating the system's ability to predict intent and tone accurately. In 2025, Fyxer grew from $1 million to $32 million in annual recurring revenue, with a strong focus on user retention. Many of Fyxer's customers are not deeply technical, and for some, Fyxer is the first AI system they use daily.

Source: openai