Large language models (LLMs) are increasingly used for high-stakes decision-making, yet existing approaches struggle to reconcile scalability, interpretability, and reproducibility. Black-box models obscure their reasoning, while recent LLM-based rule systems rely on per-sample evaluation, causing costs to scale with dataset size and introducing stochastic, hallucination-prone outputs. We propose reframing LLMs as code generators rather than per-instance evaluators. A single LLM call generates executable, human-readable decision logic that runs deterministically over structured data, eliminating per-sample LLM queries while enabling reproducible and auditable predictions. We combine code generation with automated statistical validation using precision lift, binomial significance testing, and coverage filtering, and apply cluster-based gap analysis to iteratively refine decision logic without human annotation. We instantiate this framework in venture capital founder screening, a rare-event prediction task with strong interpretability requirements. On VCBench, a benchmark of 4,500 founders with a 9% base success rate, our approach achieves 37.5% precision and an F0.5 score of 25.0%, outperforming GPT-4o (at 30.0% precision and an F0.5 score of 25.7%) while maintaining full interpretability. Each prediction traces to executable rules over human-readable attributes, demonstrating verifiable and interpretable LLM-based decision-making in practice.
Figures & tables
Method
Cost
Speed
Interpret.
Stat. valid.
Determin.
CAAFE Hollmann et al. (2023)
Low
Fast
Low
CV only
Yes
FeatLLM Balek et al. (2024)
High
Slow
High
None
No
RRF Griffin et al. (2025)
High
Slow
High
None
No
Ours
Low
Fast
High
Built-in
Yes
Table 1: Comparison with related work on automated feature engineering across five key dimensions.
Figure 1: Overview of our LLM-as-code-generator pipeline. The LLM is called once to generate executable Python rules, which then evaluate deterministically across all founders without further LLM involvement. Statistical validation filters low-quality rules, and cluster-based gap analysis guides iterative refinement.
Field
Type
Example Values
industry
string
“Software Development”
educations
list
degree, field, qs_ranking
jobs
list
role, company_size, industry, duration
ipos
list
prior IPO events
acquisitions
list
prior acquisition events
Table 2: Founder profile data structure.
Figure 2: Rule generation process. The LLM receives structured founder profiles and generates Python lambda expressions that encode binary screening rules. These rules execute deterministically across all 4,500 founders without additional LLM calls.
Metric
Threshold
Rationale
Precision lift
>1.0
Above-baseline success rate
p-value
<0.05
Statistical significance
Coverage
1%–50%
Sufficient power, meaningful discrimination
Table 3: Statistical validation criteria for rule filtering.
Method
Precision
Recall
F 0.5
Random Baseline
9.0%
9.0%
9.0%
Y Combinator
14.0%
6.9%
8.6%
Tier-1 VCs
23.0%
5.2%
10.7%
Claude-3.5-Haiku
15.8%
46.4%
18.2%
GPT-4o
30.0%
16.3%
25.7%
o3
43.2%
7.4%
21.5%
Table 4: Performance comparison on VCBench.
Figure 3: Rule quality distribution. Each point is a generated rule. Significant rules (green) cluster above the lift=1.0 threshold, with a tradeoff between lift and coverage.
Iter
Rule
Lift
Cov.
1
prior_exit
3.05 ×
3.16%
1
founder_scaled_company_200plus
2.80 ×
2.56%
1
worked_in_vc_pe
2.35 ×
3.47%
1
executive_chair_or_operating_partner
2.28 ×
2.71%
1
elite_qs_top10
2.18 ×
11.91%
2
cybersecurity_domain_depth
6.54 ×
0.38%
Table 5: Top rules by precision lift per iteration.
Appendix figures & tables2 assets
Supplementary material from the paper’s appendix.
Appendix
Rule Name
Description
Lift
Coverage
p-value
Iteration 1: Initial generation (no feedback)
prior_exit
Founder has ≥ 1 prior IPO or acquisition
3.05 ×
3.16%
< .001
founder_scaled_200plus
Founded/co-founded company that grew to 200+ employees
Security industry + technical security role experience
6.54 ×
0.38%
< .001
Appendix
Table 6: Representative generated rules with validation statistics. Iter 1 rules were generated without feedback; Iter 2 rules were guided by cluster-based gap analysis targeting underperforming subpopulations.
Metric
Iter 1
Iter 2
Rules generated
30
30
Significant (p < 0.05)
19 (63%)
21 (70%)
Mean lift (sig. rules)
1.70 ×
2.58 ×
Median lift (sig. rules)
1.46 ×
1.88 ×
Rules with lift > 2 ×
5
10
Rules with lift > 3 ×
1
6
Appendix
Table 7: Rule generation statistics per iteration. Feedback-guided generation (Iter 2) produces more significant rules with higher mean precision lift, though with lower average coverage as the LLM targets more specialized subpopulations.