Confidence-Based Routing

Confidence-based routing is the workflow pattern that turns confidence scores into paths: each document — or each field within one — is directed according to how certain the system is about it. High-confidence results flow into downstream systems automatically; mid-range results escalate to a stronger (slower, costlier) model or additional validation; low-confidence results land in human review queues; and hopeless inputs (unreadable scans, unknown document types) route to recapture or specialist handling. The pattern converts a single-quality pipeline into a tiered system that spends effort where uncertainty actually lives.

Field-level routing is the refinement that changes the economics. Routing whole documents wastes attention — one doubtful field among thirty confident ones sends the entire document to a person. Per-field routing lets the twenty-nine flow through while the reviewer sees exactly one highlighted value with its source region; the document's overall path becomes the composition of its fields' paths. Similarly, model-tier routing exploits the cost asymmetry of modern model families: a compact fast model handles the bulk of traffic, with escalation to a large vision-language model only for the regions and fields that resist — often cutting per-document cost severalfold at equal or better accuracy.

The routing fabric needs the same operational care as the models it orchestrates. Thresholds per field and tier are set from measured accuracy-versus-volume trade-offs, not intuition, and revisited as models and document mixes change. Queues need capacity management — a threshold tightened without staffing the resulting review volume just converts silent errors into missed SLAs. And the routing decisions themselves belong in the audit trail: for any processed document, the record should show which path each value took and why, because "how do you decide when a human looks?" is among the first questions any auditor of an automated document process asks.