Who writes the eval when the FDE cannot see the customer's data?

The field does, and only the rate crosses the wall. As Latent Space reports Jacob Lauritzen's November 2, 2026 interview, Legora cannot read customer traces because the data belongs to the firms' clients, so the field is split: about 100 legal engineers, former big-law lawyers, configure the product and write no code, while forward deployed engineers, the first hired about nine months earlier, write code and integrations and never touch client data. The eval lives with neither: a team of three engineers and three lawyers builds simulated environments such as a 10,000-file due-diligence data room, and production failures are sorted into roughly 10 to 20 known failure modes with cheap checks behind flags. My rule in The FDE Writes the Eval is that the eval is the customer's real cases with agreed-correct answers, written by the FDE with the customer's experts labeling. Behind a data wall that becomes: whoever sits with the customer and can see the cases holds the versioned row set and reports the go-live pass rate; the FDE owns the failure-mode list and the synthetic room and ships the checks; the handback is the list plus the rate, and the rows never travel. The renewal is priced against the rate the field reports, with the customer able to re-run the rows without you.