Prevent tomorrow's feature from leaking into yesterday
one move: respect prediction time
Open the code pane immediately, then use the Spec tab, optional design question, tests, and artifact when you want them.
Finish each move before carrying the artifact forward.
Features must be computed from information available at the prediction timestamp; otherwise offline scores lie.
Deliverable: State the invariant in one sentence.Join entity events to request timestamps and return only the latest value at or before each request.
Deliverable: Type the smallest deterministic implementation.Every request gets at most one historical value, equal timestamps are allowed, and future events are never selected.
Deliverable: Record a normal case and a boundary case.Move an event one minute into the future and confirm the training row changes or becomes missing.
Deliverable: Name the failure signal and the guard you would add.A point-in-time join report with leakage checks and missing-feature counts.
Deliverable: Save the contract, evidence, and handoff note.Every request gets at most one historical value, equal timestamps are allowed, and future events are never selected.
Move an event one minute into the future and confirm the training row changes or becomes missing.
A point-in-time join report with leakage checks and missing-feature counts.
Deriva-authored extension beyond the supplied PDF. The five moves are Deriva’s implementation contract for this project.