Jared Joselowitz describes Ufonia's approach to evaluating a clinical conversational agent before exposing patients to changes. The title's million-patient figure refers to a reported contract for future scale. The engineering argument begins with defining possible harm, such as missed warning signs or invented advice, because an already completed patient conversation cannot simply be undone by rolling back software.
Jared Joselowitz presents Matrix, a simulation framework in which an LLM plays a patient under a defined clinical scenario and converses with the target agent. The process checks whether the simulated patient follows instructions and uses patient and public feedback to assess realism. The talk emphasizes that realistic testing needs varied personas and communication styles, including rare situations that ordinary call data may not capture.
Jared Joselowitz describes an automated judge that returns structured hazard decisions and reasons, then explains how the team compared it with clinician labels. The reported performance comes from the team's study. Evaluation priorities are tied to the consequences of an error, so missing a dangerous condition can receive a different penalty from unnecessarily asking additional questions.
Jared Joselowitz connects those evaluation results to automated prompt optimization. A model reviews failures, proposes prompt changes and keeps useful candidates against an explicit metric, reducing reliance on manual adjustments. The proposed workflow retains prompt versions, data and decision traces so improvements can be inspected and connected to the hazards they are intended to address.
Jared Joselowitz explicitly states that successful simulation does not establish real patient benefit. The described progression moves through user testing, supervised clinical evaluation and monitored deployment, with autonomy increasing according to evidence. New languages and voice behaviors can introduce fresh hazards, including interruptions that prevent important information from being completed, so the safety case needs continuing revision.
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