Research

PEQY is based on quantitative and qualitative research, not just AI prompt engineering. Our database is constantly extended and improved, to make PEQY the most reliable code reviewer of the forest.

83 qualitative user interviews and counting

We conduct interviews to never develop past reality, based on real projects, problems and needs, to achieve the best solutions.

1.627 open-source repositories analyzed to date.

We analyzed thousands of open source repositories to identify the most common bug patterns that make it into production.

40 distinct bug types

40 distinct bug types have been analyzed, categorized, and optimized to power PEQY's unique, research-backed detection and remediation engine.

Bug Taxonomy

Last Update: 28 Jan 2026

Security

Severity
High
Prevalence
Low

Vulnerabilities that enable unauthorized access, data exfiltration, privilege abuse, or remote code execution.

View all 8 Security bug types >

Interface & Contract

Severity
Medium
Prevalence
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

Severity
Low
Prevalence
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

Severity
Medium
Prevalence
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

Severity
Medium
Prevalence
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

Severity
Medium
Prevalence
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

Severity
High
Prevalence
Low

Improper allocation/lifetime of memory, handles, or descriptors leading to leaks or corruption.

View all 4 Memory & Resource Management bug types >

Performance

Severity
Low
Prevalence
Low

Inefficiencies on critical paths (blocking work, pathological regexes, sync work in async flows).

View all 3 Performance bug types >

Do you want to contribute to our code quality research project?

Are you interested in PEQY, do you want to leave feedback or join our team? We are always happy to chat with likeminded devs, interested decision makers or start-up enthusiasts.