The collection

Pick an app. Load a bug.

Every app in the collection is a real product fiction with defects planted in it. Open one and free-hunt, or load a specific bug type and the app renders with exactly that defect in scope.

Or start from a bug type →

QualityChart

St. Quality Health · Healthcare · EHRqualitychart.stquality.test

A hospital patient portal over FHIR services, an HL7 intake pipeline, and an ambient clinical AI — one synthetic patient journey across all of them.

Load a bug:Pagination drops a page Derived value never invalidates · account Number carried as a string Control has no accessible name Value shown without its qualifier Threshold set at the wrong boundary · account Failure mapped to the wrong status Only the first of a repeating group is kept Transform shifts a date AI asserts something not in the record · account AI recommendation contradicts the record · account

Run a pack:The pipeline pack The AI-under-audit pack

Mock infra: HL7 → FHIR Bridges (etl) · Clinical Copilot (ai)

Open QualityChart →13 planted defects across 11 bug types

TapTrust Federal

TapTrust Federal Credit Union · Banking · Online + telleronline.taptrustfederal.test

A full online bank: client portal with accounts and transfers, a teller console with an approval queue and ledger, an architecture map, and live request traces — money movement with every place money math goes wrong.

Load a bug:Pagination drops a page Derived value never invalidates Zero or negative amount accepted Object-level authorization missing Idempotency key accepted but ignored Concurrent writes lose an update Money handled as floating point Threshold set at the wrong boundary Internal field leaks into a public payload

Run a pack:The money pack The broken-trust pack The retry-storm pack The AI-under-audit pack

Open TapTrust Federal →12 planted defects across 9 bug types

QualityMart

QualityMart Inc. · Retail · Big-box e-commerceshop.qualitymart.test

A big-box online retailer — catalog, carts, coupons, inventory, and checkout. Every classic commerce flow, each hiding a classic commerce defect.

Load a bug:Pagination drops a page Zero or negative amount accepted Sort uses the wrong comparator Object-level authorization missing Idempotency key accepted but ignored Concurrent writes lose an update Money handled as floating point

Run a pack:The money pack The retry-storm pack

Open QualityMart →9 planted defects across 7 bug types

Add your app to the collection

An app is a manifest, a rendered surface, and a set of planted defects bound to the shared bug-type catalog. Implement the bug types the collection already grades and your app becomes a hunting ground for every existing challenge — see CONTRIBUTING.md.

Suggest a playground →

Archive — v1 playgrounds

The first generation of single-aspect playgrounds. Deprecated as standalone destinations — what each one taught now lives in the bug-type catalog and is seeded across the apps above — but each one and its planted defects remain reachable.

Legacy Shop TapTrust Teller Acme Internal APIs Pipeline Infra AI QA Workbench Flaky Suite A11y Clinic Release Console Mobile Shopfront Perf Benchmarks Prompt Security Harness