Credit Engine backtest

5,000 synthetic borrowers run through /v1/evaluate. The engine never sees the ground-truth default columns — they only score the result.

Approval rate
10.0%
All-comers default
17.7%
Approved-book default
3.4%
Risk separation
Monotonic ✓
Grade × default rate (risk must rise as grade worsens)
GradeLabelCountShareDefault rate
1Premium3947.9%3.6%
2Elite941.9%3.2%
3Prime90.2%0.0%
4Standard20.0%0.0%
7Sub-prime10.0%0.0%
rejectReject450090.0%19.2%
Approved book vs all-comers
All-comers17.7%
Approved book3.4%
Rejected pool19.2%

The engine lifts the book from 17.7% to 3.4% by declining the riskiest 90.0%.

Risk separation
Grade 1 default: 3.6%
Grade 10 default: 3.2%
Monotonic: yes — default rises every grade