Case study · GTM / RevOps

Reply Classifier Cascade

A cost-ordered classifier for English and Dutch cold-email replies that decides which replies become CRM deals, built so a false “hot deal” needs several layers to agree.

Open sourceGTM / RevOps
  1. 1The problem

    Keyword filters match the quoted thread, miss negation and miss implicit interest; a single model is confidently wrong. A false deal wastes sales time and corrupts pipeline numbers.

  2. 2Our contribution

    Designed and built end to end by Kumar Sahil.

  3. 3What we built

    A five-layer cascade: platform flag (vetoable), anchored EN/NL regex rules, an LLM with a confidence floor, a Naive Bayes fallback that can’t create a deal without a non-negated positive cue, and a keyword safety net that routes to a human. Free deterministic layers settle most replies first, so the paid model only sees the hard ones.

  4. 4The result

    Released as open source. Read the code, tests and design notes on GitHub.

Technology
Python 3.11
Naive Bayes
LLM classification
Smartlead / Instantly
HubSpot
More work

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LLM Eval Gauntlet

Invariant-checked evaluation suites for tool-calling agents that run in CI and fail the build when an agent invents a number, leaks its prompt or obeys an injection.Read the case study
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