Most AI products are built by technologists and deployed to professionals. The technologists understand the models. The professionals understand the domain. The two rarely meet in a way that changes what the product actually encodes.
"Built by experts to serve experts" describes a different model — one in which the people who possess mastered domain knowledge are not the eventual end users of the AI, but its co-authors. They are present at the point of knowledge construction, not the point of deployment. What they know shapes what the AI can do. Their judgment, encoded, is what the product delivers to the professionals who use it.
This distinction sounds subtle. Its consequences are not.
What "built by experts" actually requires
The phrase "expert-built" is increasingly used as a marketing descriptor. It often means that an expert was consulted during development, that the dataset was sourced from a domain-specific corpus, or that a practitioner reviewed the outputs before release. These are all better than nothing. None of them are what built by experts means in the strict sense.
To be built by an expert, an AI product must carry the expert's knowledge as its primary source — not as a validation layer on top of generally-derived training. This requires a fundamentally different process: one that starts with structured elicitation of tacit practitioner knowledge, converts that knowledge into explicit reasoning chains, and uses those chains as the foundation on which the AI product is built.
The expert, in this model, is not a consultant. They are a collaborator whose intellectual contribution is the product's core asset. The knowledge they bring — their edge-case handling, their weighted judgments, their understanding of when standard approaches fail — cannot be sourced from any database. It exists only in them, accumulated over careers of practice. Extracting it, structuring it, and making it operational is the work.
The difference between validation and co-authorship is the difference between a product that passes an expert's review and one that carries their judgment.
What "serve experts" means
The second half of the positioning is equally precise. The intended audience of an expert-built AI product is not the general public, or even a general professional audience. It is the practitioners who work within the specific domain the AI serves — people who already possess significant domain knowledge, who can evaluate the AI's outputs against their own experience, and who require a tool that operates at the level of their practice rather than below it.
This changes what the product needs to do. Consumer AI is designed to be accessible — to lower the barrier to information, to provide useful approximations to people who lack domain knowledge. A product built to serve experts does not need to explain the basics. It needs to handle the hard cases. It needs to surface the judgment that even experienced practitioners would benefit from — the encoded knowledge of a practitioner who is, in some specific respect, more experienced or more deeply specialised than the person using the tool.
A cardiothoracic surgeon using a surgical decision-support AI is not looking for a general-purpose clinical information tool. They need something that operates at the level of a peer — that carries the judgment of another experienced surgeon, available at the moment they need it. That is a categorically different requirement from what generic clinical AI delivers.
Why co-development produces different outcomes
There is a practical reason why co-development with domain experts produces better AI products in professional settings: it surfaces knowledge that cannot be accessed any other way.
Published literature represents the knowledge that domain practitioners chose to write down. It is extensive, but it is systematically incomplete in one important respect: it contains very little of the tacit knowledge that separates expert performance from competent performance. The judgment calls, the pattern recognition across thousands of prior cases, the knowing when not to act — these are transmitted through practice, not publication. They do not appear in training datasets. They cannot be derived from literature, however voluminous.
Co-development with a domain expert creates a pathway for this knowledge to enter the product. Through structured sessions designed to surface tacit reasoning — through case analysis, edge-case mapping, and explicit protocol documentation — the product captures knowledge that no training corpus contains. This is the substantive advantage of the approach, and it is not replicable through any amount of additional general training data.
The standard applied: how Praxa builds
Praxa applies this standard precisely. Each product is built in close collaboration with a single recognised domain practitioner — someone whose judgment is trusted by peers, not merely credentialed. The practitioner contributes as a co-author, not a reviewer. Their knowledge becomes the foundation of the product, not a validation layer applied after the fact.
The resulting product is narrow by design. It addresses one problem, in one domain, drawing on the knowledge of one expert. That narrowness is not a limitation — it is what makes the product trustworthy in the cases that matter. An AI product that claims to serve medicine broadly will, at best, approximate the performance of an average practitioner across all contexts. An AI product built with a cardiothoracic surgeon to address a specific class of intraoperative decisions will exceed the performance of most practitioners in precisely those decisions — because it carries the judgment of someone who has spent a career on them.
This is the practical meaning of built by experts to serve experts: products that earn trust from professionals because they operate at the level of professional practice, not below it. That standard requires a different process, a different kind of collaboration, and a different conception of what a domain expert contributes. It also, when done well, produces a categorically different outcome.
For a deeper look at the methodology, see AI and Domain Expert Collaboration and What Are Domain Expert AI Products. To meet Praxa's expert collaborators, visit the Experts section.