Bulk Import Engineering

Keep validation, preview, execution, and status tied to the same import operation.

When the import or export runs against client-side storage rather than a server, follow local import and export.

Trace the server contract

Before changing the flow, inspect the backend contract for validation, execution, status, retries, permissions, and concurrent submissions. Trace how the selected file and import options are associated with the validation result and preview. Follow existing capabilities and make gaps visible; do not invent endpoints or assume the UI defines server behavior.

Bind preview to its inputs

Treat a preview as valid only for the file contents and options that were validated. Replacing or editing either invalidates that preview and requires validation again before execution. Keep execution as an explicit action after review; validation and preview must not commit imported work.

If preview rows are editable, establish how the server validates the edited revision and binds execution to it. Ignore obsolete validation responses so an earlier selection cannot replace the current preview.

Represent pending, in-progress, successful, partial, and failed outcomes according to the server contract. Define retry and reset behavior from that contract, including whether retry applies to failed items or the whole operation. Do not assume every import is atomic. A lost response does not prove that no work occurred.