Understand the failure.
Verify the repair.
Small, reproducible software failures. The broken implementation, the fix that didn’t work, and the one that passed—preserved together.
Explore the cases ↓How results are verified ↗WHAT THE ARCHIVE CONTAINS
100840 executable cases. 20168 are open.
Every case records the implementation that fails, the fix that did not work, and the repair that passed its checks—with recorded outputs and source hashes. This release adds 100840 cases across 20168 failure mechanisms and 254 domains.
The open tier gives you the failure and the unsuccessful fix for one case in every mechanism. The remaining 80672 cases, 5 variants per mechanism, are member-only: the verified repair, its recorded checks, and the full fixture suite are held in the member archive. Read the methodology ↗
A RECORD OF WHAT WENT WRONG
Browse the archive / 100840
Payment application waterfall: new balance reduction · case 01
Scheduled principal payments do not lower the reported balance.
Payment application waterfall: new balance reduction · case 02
Scheduled principal payments do not lower the reported balance.
Payment application waterfall: new balance reduction · case 03
Scheduled principal payments do not lower the reported balance.
Payment application waterfall: new balance reduction · case 04
Scheduled principal payments do not lower the reported balance.
Payment application waterfall: new balance reduction · case 05
Scheduled principal payments do not lower the reported balance.
Payment application waterfall: held funds amount · case 01
Suspense loses its prior balance when another short payment arrives.
Payment application waterfall: held funds amount · case 02
Suspense loses its prior balance when another short payment arrives.
Payment application waterfall: held funds amount · case 03
Suspense loses its prior balance when another short payment arrives.
Payment application waterfall: held funds amount · case 04
Suspense loses its prior balance when another short payment arrives.
Payment application waterfall: held funds amount · case 05
Suspense loses its prior balance when another short payment arrives.
Late fee after grace period: grace deadline inclusivity · case 01
A payment received on the last grace day is charged a late fee.
Late fee after grace period: grace deadline inclusivity · case 02
A payment received on the last grace day is charged a late fee.
Late fee after grace period: grace deadline inclusivity · case 03
A payment received on the last grace day is charged a late fee.
Late fee after grace period: grace deadline inclusivity · case 04
A payment received on the last grace day is charged a late fee.
Late fee after grace period: grace deadline inclusivity · case 05
A payment received on the last grace day is charged a late fee.
Late fee after grace period: shortfall tolerance · case 01
Payments a few cents short are treated as late.
Late fee after grace period: shortfall tolerance · case 02
Payments a few cents short are treated as late.
Late fee after grace period: shortfall tolerance · case 03
Payments a few cents short are treated as late.
Late fee after grace period: shortfall tolerance · case 04
Payments a few cents short are treated as late.
Late fee after grace period: shortfall tolerance · case 05
Payments a few cents short are treated as late.
Late fee after grace period: days late origin · case 01
Days late are understated by the grace period.
Late fee after grace period: days late origin · case 02
Days late are understated by the grace period.
Late fee after grace period: days late origin · case 03
Days late are understated by the grace period.
Late fee after grace period: days late origin · case 04
Days late are understated by the grace period.
Late fee after grace period: days late origin · case 05
Days late are understated by the grace period.
Late fee after grace period: fee floor · case 01
Late fees on small payments fall below the contractual minimum.
Late fee after grace period: fee floor · case 02
Late fees on small payments fall below the contractual minimum.
Late fee after grace period: fee floor · case 03
Late fees on small payments fall below the contractual minimum.
Late fee after grace period: fee floor · case 04
Late fees on small payments fall below the contractual minimum.
Late fee after grace period: fee floor · case 05
Late fees on small payments fall below the contractual minimum.
Late fee after grace period: unpaid lateness end · case 01
Late payments report lateness up to the statement date instead of the payment date.
Late fee after grace period: unpaid lateness end · case 02
Late payments report lateness up to the statement date instead of the payment date.
Late fee after grace period: unpaid lateness end · case 03
Late payments report lateness up to the statement date instead of the payment date.
Late fee after grace period: unpaid lateness end · case 04
Late payments report lateness up to the statement date instead of the payment date.
Late fee after grace period: unpaid lateness end · case 05
Late payments report lateness up to the statement date instead of the payment date.
Late fee after grace period: fee base · case 01
Late but complete payments are charged only the minimum fee.
Late fee after grace period: fee base · case 02
Late but complete payments are charged only the minimum fee.
Late fee after grace period: fee base · case 03
Late but complete payments are charged only the minimum fee.
Late fee after grace period: fee base · case 04
Late but complete payments are charged only the minimum fee.
Late fee after grace period: fee base · case 05
Late but complete payments are charged only the minimum fee.
Adjustable rate reset with caps: first adjustment cap · case 01
The first reset is limited by the periodic cap instead of the initial cap.
Adjustable rate reset with caps: first adjustment cap · case 02
The first reset is limited by the periodic cap instead of the initial cap.
Adjustable rate reset with caps: first adjustment cap · case 03
The first reset is limited by the periodic cap instead of the initial cap.
Adjustable rate reset with caps: first adjustment cap · case 04
The first reset is limited by the periodic cap instead of the initial cap.
Adjustable rate reset with caps: first adjustment cap · case 05
The first reset is limited by the periodic cap instead of the initial cap.
Adjustable rate reset with caps: lifetime ceiling base · case 01
Note rates are pinned to the lifetime cap spread itself.
Adjustable rate reset with caps: lifetime ceiling base · case 02
Note rates are pinned to the lifetime cap spread itself.
Adjustable rate reset with caps: lifetime ceiling base · case 03
Note rates are pinned to the lifetime cap spread itself.
Adjustable rate reset with caps: lifetime ceiling base · case 04
Note rates are pinned to the lifetime cap spread itself.
Adjustable rate reset with caps: lifetime ceiling base · case 05
Note rates are pinned to the lifetime cap spread itself.
Adjustable rate reset with caps: downward adjustment cap · case 01
The note rate drops by more than the cap when the index falls.
Adjustable rate reset with caps: downward adjustment cap · case 02
The note rate drops by more than the cap when the index falls.
Adjustable rate reset with caps: downward adjustment cap · case 03
The note rate drops by more than the cap when the index falls.
Adjustable rate reset with caps: downward adjustment cap · case 04
The note rate drops by more than the cap when the index falls.
Adjustable rate reset with caps: downward adjustment cap · case 05
The note rate drops by more than the cap when the index falls.
Adjustable rate reset with caps: rate increment rounding · case 01
Fully indexed rates are always rounded up to the next increment.
Adjustable rate reset with caps: rate increment rounding · case 02
Fully indexed rates are always rounded up to the next increment.
Adjustable rate reset with caps: rate increment rounding · case 03
Fully indexed rates are always rounded up to the next increment.
Adjustable rate reset with caps: rate increment rounding · case 04
Fully indexed rates are always rounded up to the next increment.
Adjustable rate reset with caps: rate increment rounding · case 05
Fully indexed rates are always rounded up to the next increment.
Adjustable rate reset with caps: floor application · case 01
Note rates fall below the contractual floor.
Adjustable rate reset with caps: floor application · case 02
Note rates fall below the contractual floor.
Adjustable rate reset with caps: floor application · case 03
Note rates fall below the contractual floor.
Adjustable rate reset with caps: floor application · case 04
Note rates fall below the contractual floor.
Adjustable rate reset with caps: floor application · case 05
Note rates fall below the contractual floor.
Adjustable rate reset with caps: cap reference rate · case 01
Later resets jump by more than the periodic cap from the prior note rate.
Adjustable rate reset with caps: cap reference rate · case 02
Later resets jump by more than the periodic cap from the prior note rate.
Adjustable rate reset with caps: cap reference rate · case 03
Later resets jump by more than the periodic cap from the prior note rate.
Adjustable rate reset with caps: cap reference rate · case 04
Later resets jump by more than the periodic cap from the prior note rate.
Adjustable rate reset with caps: cap reference rate · case 05
Later resets jump by more than the periodic cap from the prior note rate.
Balloon maturity payment: amortization basis · case 01
Balloon loans are quoted fully amortizing payments over the short term.
Balloon maturity payment: amortization basis · case 02
Balloon loans are quoted fully amortizing payments over the short term.
Balloon maturity payment: amortization basis · case 03
Balloon loans are quoted fully amortizing payments over the short term.
Balloon maturity payment: amortization basis · case 04
Balloon loans are quoted fully amortizing payments over the short term.
Balloon maturity payment: amortization basis · case 05
Balloon loans are quoted fully amortizing payments over the short term.
Balloon maturity payment: maturity month · case 01
Loans whose amortization ends before the term keep charging payments into negative balances.
Balloon maturity payment: maturity month · case 02
Loans whose amortization ends before the term keep charging payments into negative balances.
Balloon maturity payment: maturity month · case 03
Loans whose amortization ends before the term keep charging payments into negative balances.
Balloon maturity payment: maturity month · case 04
Loans whose amortization ends before the term keep charging payments into negative balances.
Balloon maturity payment: maturity month · case 05
Loans whose amortization ends before the term keep charging payments into negative balances.
Balloon maturity payment: balloon payment composition · case 01
The balloon payment is inflated by a full regular payment.
Balloon maturity payment: balloon payment composition · case 02
The balloon payment is inflated by a full regular payment.
Balloon maturity payment: balloon payment composition · case 03
The balloon payment is inflated by a full regular payment.
Balloon maturity payment: balloon payment composition · case 04
The balloon payment is inflated by a full regular payment.
Balloon maturity payment: balloon payment composition · case 05
The balloon payment is inflated by a full regular payment.
Balloon maturity payment: interest total scope · case 01
Total interest excludes the interest in the balloon payment.
Balloon maturity payment: interest total scope · case 02
Total interest excludes the interest in the balloon payment.
Balloon maturity payment: interest total scope · case 03
Total interest excludes the interest in the balloon payment.
Balloon maturity payment: interest total scope · case 04
Total interest excludes the interest in the balloon payment.
Balloon maturity payment: interest total scope · case 05
Total interest excludes the interest in the balloon payment.
Negative amortization cap recast: cap threshold scale · case 01
Loans recast at the first cent of negative amortization.
Negative amortization cap recast: cap threshold scale · case 02
Loans recast at the first cent of negative amortization.
Negative amortization cap recast: cap threshold scale · case 03
Loans recast at the first cent of negative amortization.
Negative amortization cap recast: cap threshold scale · case 04
Loans recast at the first cent of negative amortization.
Negative amortization cap recast: cap threshold scale · case 05
Loans recast at the first cent of negative amortization.
Negative amortization cap recast: recast principal · case 01
The recast payment leaves capitalized interest unamortized.
Negative amortization cap recast: recast principal · case 02
The recast payment leaves capitalized interest unamortized.
Negative amortization cap recast: recast principal · case 03
The recast payment leaves capitalized interest unamortized.
Negative amortization cap recast: recast principal · case 04
The recast payment leaves capitalized interest unamortized.
Negative amortization cap recast: recast principal · case 05
The recast payment leaves capitalized interest unamortized.
INSPECTABLE BY DESIGN
Every result has a runnable source.
Runnable implementations with recorded outputs, source hashes, and explicit contracts. Related variants share a failure mechanism and belong together in evaluation splits.
Read the methodology ↗