1) Most critical vulnerability The exporter/importer field mismatch is the confirmed stability failure: the exporter produces `id`, while the importer reads `record_id`. Every current fixture import raises `KeyError: record_id`, blocking imports. 2) Concrete mitigation measures - Align the exporter and importer on one canonical identifier field. - Validate required fields before database writes; report missing fields as schema validation errors. - Enforce identifier uniqueness in PostgreSQL to prevent duplicate inserts. - Use transactions for atomic imports. After a timeout with an uncertain commit outcome, check persisted identifiers before retrying. - Handle HTTP 401 explicitly and report authentication failure. - Record validation failures and transaction outcomes in the existing redacted logs. 3) Recommended tests - Import a current fixture containing `id`; verify successful validation and insertion after the fix. - Supply a missing identifier or invalid row; verify controlled rejection. - Import duplicate identifiers, including by retrying the same fixture; verify no duplicate records. - Simulate timeouts before and after commit; verify database state and safe retry behavior. - Return HTTP 401; verify explicit failure reporting. - Compare validated input records with persisted records and the operator report. 4) Warning signs for future errors - Recurring `KeyError` or missing-field validation failures. - Rising failed execution counts. - Duplicate-identifier database errors. - Timeouts without a recorded transaction outcome. - Repeated HTTP 401 responses. - Differences between validated records, database records, and operator reports.