LLM Complaint Detection

LLM evaluation · Real-time NLP · Capital One

I built a generative complaint-detection model and, more importantly, the evaluation around it — anchored to a real ground-truth proxy instead of a convenient one. Status honesty: validated in production code, piloting in 2026 — not yet shipped.

This is a deliberately high-level account of proprietary work at Capital One — the problem, my role, and the approach, described qualitatively. It contains no confidential figures, internal systems, data, models, code, vendor or team names, or architecture.

Generative AIComplaint capture
High precisionvs legacy flag
PilotingValidated in prod code

From frustration phrases to policy-aware detection

The legacy approach was a hand-trained sentiment flag (with limited precision even on its own training data) that fired on frustration phrases. The replacement is an open-source GPT-based model used generatively: it produces a complaint rationale and an escalation prediction, and it detects more than frustration — policy-based escalation drivers are built into the detection logic.

The evaluation design (the part worth asking about)

There is no clean labeled set of “all complaints,” so I chose a real-world ground-truth proxy: known complaint escalations — calls escalated to a specialized support tier — over a month of production data. The legacy flag caught only a small fraction of them; the generative model captured a large majority, at a precision agents and QA can trust. The residual it cannot catch is structural: cases an agent escalates proactively from something they see on screen, with no customer-side trigger in the conversation. Knowing where the ceiling is — and why — is part of the result.

My role & status

Solo on this one: I implemented the model in production code and did the full analysis myself. The result earned an internal excellence award. To be precise about status: it is validated but not yet piloted — a pilot is planned for 2026, and I'm doing the streaming-pipeline work to bring real-time inference in-house.

Why it matters beyond the metric

Complaint capture is a compliance surface — a missed complaint is a missed obligation. Moving capture up sharply, at a precision agents and QA can trust, and with a documented account of what the system can't see, is the difference between a demo metric and an operable control.