Research
PEQY is built on research into how AL and Business Central code fails in practice: interviews with BC practitioners, the community's hard-won pitfalls, Microsoft's documentation and the BCQuality knowledge base, distilled into a taxonomy the reviewer applies on every pull request. That taxonomy is constantly extended and improved, to make PEQY the most reliable code reviewer of the forest.
We measured GitHub Copilot's review on real BC pull requests. Every compile error it claimed was refuted by the AL compiler. PEQY compile-checks its own findings against that same compiler before posting them.
Our fork of bc2adls replays real feature commits whose bugs shipped and were fixed upstream months later. PEQY's reviews are public, with provenance links to the upstream fixes. See them on GitHub.
40 distinct bug types, distilled from how AL and Business Central code fails in practice, power the taxonomy PEQY applies on every pull request.
Bug taxonomy
Last update: 25 Aug 2026
Security
High
Low
Vulnerabilities that enable unauthorized access, data exfiltration, privilege abuse, or remote code execution.
View all 8 Security bug types >Interface & Contract
Medium
High
Breaks or drifts in schemas, types, and API contracts between components/services causing integration failures.
View all 4 Interface & Contract bug types >Functional Logic & Control Flow
Low
High
Incorrect branching, conditions, or arithmetic that produce wrong outcomes or hit impossible paths.
View all 7 Functional Logic & Control Flow bug types >State & Data Consistency
Medium
Medium
Violations of domain invariants or data integrity (e.g., duplicates, mismatched aggregates, migration drift).
View all 3 State & Data Consistency bug types >Concurrency, Async & Events
Medium
Medium
Timing/order issues across threads/tasks/events (races, TOCTOU, double-exec, stale cache).
View all 5 Concurrency, Async & Events bug types >Error Handling & Input Validation
Medium
Medium
Missing or incorrect validation/handling that lets bad inputs or exceptions cascade into failures.
View all 6 Error Handling & Input Validation bug types >Memory & Resource Management
High
Low
Improper allocation/lifetime of memory, handles, or descriptors leading to leaks or corruption.
View all 4 Memory & Resource Management bug types >Performance
Low
Low
Inefficiencies on critical paths (blocking work, pathological regexes, sync work in async flows).
View all 3 Performance bug types >Know a failure mode we should cover?
If you work in AL and there is a bug class the taxonomy is missing, or you want to see PEQY review your own pull requests, we are happy to talk.