Databases

React 19 with TypeScript 5.9.3, TanStack Query V5, Zustand, and modern patterns. React Compiler handles memoization automatically. No manual optimization needed.

Uses Redis for caching, sessions, pub/sub, and data structures with Node.js. Use when implementing caching, session storage, real-time messaging, or high-performance data storage.

Type-safe ORM for Cloudflare D1 databases using Drizzle. This skill provides comprehensivepatterns for schema definition, migrations management, type-safe queries, relations, andCloudflare Workers integration.Use when: building D1 database schemas, writing type-safe SQL queries, managing databasemigrations with Drizzle Kit, defining table relations, implementing prepared statements,using D1 batch API for transactions, or encountering "D1_ERROR", transaction errors,foreign key constraint failures, migration apply errors, or schema inference issues.Prevents 12 documented issues: D1 transaction errors (SQL BEGIN not supported), foreign keyconstraint failures during migrations, module import errors with Wrangler, D1 binding not found,migration apply failures, schema TypeScript inference errors, prepared statement caching issues,transaction rollback patterns, TypeScript strict mode errors, drizzle.config.ts not found,remote vs local database confusion, and wrangler.toml vs wrangler.jsonc mixing.Keyw

Use when reviewing pull requests. Covers PR examination, code quality checks, adding feedback, and pass/fail decisions.

Use this skill whenever the user wants to create, restructure, or standardize a NestJS backend project in TypeScript, including folder layout, config, environment setup, tooling, and initial integrations (TypeORM-ready, testing-ready, and deployment-friendly).

Test escape room difficulty, collect player metrics, identify stuck points, and balance gameplay for 60-70% completion rate target. Implements alpha/beta testing protocols, feedback analysis, and iterative difficulty adjustment. Use when validating game balance, analyzing player behavior, or optimizing escape room challenge levels.

Integration templates for FastAPI endpoints, Next.js UI components, and Supabase schemas for ML model deployment. Use when deploying ML models, creating inference APIs, building ML prediction UIs, designing ML database schemas, integrating trained models with applications, or when user mentions FastAPI ML endpoints, prediction forms, model serving, ML API deployment, inference integration, or production ML deployment.

Query and manage local tRPC documentation mirror (25 docs). Search tRPC topics for end-to-end typesafe APIs, routers, procedures, React Query integration, and Next.js setup. Use when implementing tRPC features or answering tRPC-related questions. (user)

REST integration testing patterns with JUnit 5, Mockito, RestAssured. Use when writing integration tests that mock external dependencies, use Testcontainers/H2 for databases, and test endpoints with raw JSON bodies.

Language-agnostic backend patterns: API design, authentication, security, databases.Use when: designing APIs, implementing auth, securing endpoints, modeling data.Triggers: "api design", "rest api", "graphql", "authentication", "jwt", "oauth","security", "owasp", "database schema", "migrations", "sql".

Database operation rules (SeaORM, migrations, transaction rules, PostgreSQL). Use when working with database, creating migrations, using SeaORM, asking about DB operations, schema changes, queries, or entity definitions.

AGGRESSIVELY use TOON v2.0 format for biggish regular data (≥5 items, ≥60% uniform). Auto-applies to tables, logs, events, transactions, analytics, API responses, database results. Supports 3 array types (inline, tabular, expanded), 3 delimiters (comma, tab, pipe), key folding for nested objects. Triggers on structured data, arrays, repeated patterns. Use TOON by default when tokens matter - RAG pipelines, tool calls, agents, benchmarks. Keywords "data", "array", "list", "table", "log", "transaction", "metric", "analytics", "API", "database", "query", "TOON".

Patterns and best practices for Better-T-Stack projects (TanStack Router, Hono, Drizzle, tRPC, Better Auth)

Systematically retrieve and address PR code review comments using make pr-comments. Enforces DDD architecture, code organization principles, and quality standards. Use when handling code review feedback, refactoring based on reviewer suggestions, or addressing PR comments.

Detects N+1 queries, suggests eager loading, and recommends database indexes

Master SQL query optimization, indexing strategies, and EXPLAIN analysis to dramatically improve database performance and eliminate slow queries. Use when debugging slow queries, designing database schemas, or optimizing application performance.

AI-powered Signal Factory Core for processing observability signals and maintaining the knowledge graph. Use when: (1) Developing Signal Engines (Freshness, Drift, Contract, DQ, Volume, Anomaly), (2) Configuring Signal Router for normalization and routing, (3) Designing Neptune graph schema for assets and lineage, (4) Implementing DynamoDB state management for incidents. Triggers: "create signal engine", "configure signal router", "design graph schema", "implement signal processing".

Domain-specific development mode guidelines for UI, API, database, integration, migration, and specialized workflows. Each mode provides tailored principles, checklists, and patterns for different types of development work.

SQL query optimization, schema design, indexing, and relational database mastery

Use when working with rwsdk/db for SQLite Durable Objects - covers setup with migrations, type-safe queries with Kysely, CRUD operations, joins, seeding, and migration rollback handling in Cloudflare Workers environments