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Prototype / Lab ExperimentSpring 2026990Labs Systems Team

Deterministic Inbound Qualification & Webhook Router

We built an autonomous inbound qualification prototype to test whether deterministic scoring beats conversational LLMs for inbound lead triage.

Direct Answer & Core Finding

Heuristic scoring gates and instant DNS verification beat open-ended LLMs for inbound qualification.

1. The Baseline Problem

Manual form review queues often created a 4-hour delay before high-intent prospects received calendar booking links.

The problem with most inbound qualification isn't intelligence—it is latency. When high-fit prospects submit a form, human review queues introduce friction.

In this lab spike, we evaluated three architectures: pure conversational chatbot, unconstrained LLM summary, and deterministic rules paired with targeted enrichment.

2. What Was Built

A webhook listener that validates business domain records, cross-references enrichment APIs, and routes qualified leads directly to Calendly.

The pure LLM approach suffered from inconsistent latency (8-15 seconds) and occasional misclassification on non-traditional email domains.

The hybrid solution: deterministic criteria (verified email MX record, company headcount tier, clear budget trigger) evaluated in <200ms. High-fit leads are immediately redirected to calendar booking.

What Broke & Known Limitations

Unconstrained LLM prompts frequently miscategorized unusual company domain extensions (.so, .ai). We replaced free-form prompting with deterministic regex rules and verified DNS MX record checks.

Related Services & Next Steps

If your organization is dealing with similar operational bottlenecks, explore our related engineering services or book an architecture audit.

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