Expo apps often need native device features with careful permissions and platform handling. This skill provides focused patterns for adding camera, notifications, haptics, location, storage, app state, and keyboard behavior.

Expo authentication often fails because OAuth redirects, token storage, and route guards must align across app and backend. This skill provides concrete React Native patterns for Google sign-in, secure token handling, protected routes, and backend token verification.

React Native async bugs can hide in state actions, effects, and promise chains. This skill guides Claude, Codex, and Claude Code through focused async reviews and safer sequencing decisions.

React teams can hit stale state, render timing, and async action bugs when using Zustand. This skill gives direct patterns for stores, selectors, derived state, testing, debugging, and persistence.

React test suites often become flaky when async state, providers, and mocks are handled inconsistently. This skill gives Claude, Codex, and Claude Code practical patterns for focused React tests.

Complex React flows often fail through missed awaits, hidden transitions, and weak error states. This skill guides explicit state design, validation, UI feedback, and integration tests.

React apps can slow down because renders, lists, bundles, images, and heavy computations grow unnoticed. This skill gives practical patterns for diagnosing and reducing those costs.

React failures often hide behind silent returns and weak error messages. This skill gives Claude, Codex, and Claude Code practical patterns for logs, tracing, and safer diagnostics.

Async React bugs create race conditions, missed state updates, and unreliable effects. This skill guides reviews, fixes, and lint rules for safer async code.

Async Python tests can fail silently, leak database state, or miss awaited behavior. This skill gives pytest-asyncio patterns for fixtures, mocks, HTTP clients, and full-flow tests.

SQLModel async projects often fail from lazy loading, schema drift, and session mistakes. This skill gives focused patterns for models, queries, relationships, and ORM debugging.

Pydantic v1 habits can cause validation and serialization defects. This skill provides Pydantic v2 patterns for schemas, validators, configuration, unions, and serialization.

Python services are difficult to debug when logs, metrics, and traces are inconsistent. This skill provides practical patterns for structured logging, Prometheus metrics, Sentry setup, health checks, and redaction.

FastAPI projects often drift into inconsistent routes, responses, and schemas. This skill gives practical patterns for endpoints, validation, errors, middleware, and OpenAPI.

Async Python code can leak sessions, block responses, and deadlock under load. This skill gives FastAPI and SQLAlchemy patterns for safer async database work.

Alembic autogenerate can create migrations that lose data or lock tables. This skill gives practical PostgreSQL patterns for safer schema changes, reviews, testing, and production rollout.

Slow database queries harm application reliability and scale. This skill gives practical PostgreSQL patterns for faster queries, safer migrations, and clearer monitoring.

PostgreSQL migrations can pass tests while causing locks, slow scans, or index bloat. This skill gives Claude, Codex, and Claude Code practical patterns for safer schema and query review.

iOS release work for Expo apps requires EAS profiles, credentials, TestFlight steps, and version rules. This skill gives focused checklists and commands for build, submit, OTA updates, and troubleshooting.

Expo apps often hide broken API flows, unsafe token handling, and stale screen data. This skill guides Claude, Codex, or Claude Code through a structured API audit.