Jeffallan Skills

Builds NestJS backend features in TypeScript, from modular architecture and dependency injection to validation, authentication and tests.

Builds and configures Laravel 10+ applications with Eloquent, Sanctum, queues, APIs, Livewire interfaces and Pest or PHPUnit tests.

Implements idiomatic Go applications with concurrency, microservices, generics, testing and performance profiling using goroutines, channels and pprof.

Builds modern PHP applications and APIs with Laravel or Symfony, strict typing, dependency injection, PSR standards, static analysis and tests.

Builds Flutter 3+ cross-platform applications with Dart, covering widgets, Riverpod or Bloc state, GoRouter navigation, testing and performance.

Builds Spring Boot 3.x services with REST APIs, security, data access and reactive WebFlux endpoints using layered Java architecture.

Builds type-safe Python 3.11+ applications with async patterns, pytest tests, strict mypy checks and linted formatting.

Designs high-level system architectures, diagrams, ADRs and technology choices with explicit trade-offs for scalability and operations.

Builds WebSocket and Socket.IO systems with authenticated events, room management, Redis scaling, reconnection, presence and operational checks.

Builds and validates firmware for microcontrollers, RTOS applications and bare-metal systems, with attention to interrupts, peripherals, timing and power use.

Reviews code diffs and files for bugs, security vulnerabilities, performance problems and maintainability issues, then produces prioritised feedback.

Designs REST and GraphQL APIs with resource models, OpenAPI 3.1 specifications, pagination, errors and versioning strategies.

Optimizes SQL queries and database schemas across PostgreSQL, MySQL, SQL Server and Oracle using execution plans, indexes and set-based patterns.

Builds game systems for Unity and Unreal Engine, covering architecture, physics, networking, shaders, AI and performance profiling.

Writes, reviews and debugs idiomatic Rust with safe ownership, trait-based APIs, async Tokio code and explicit error handling.

Builds async FastAPI APIs with Pydantic V2, authentication and OpenAPI documentation.

Writes, debugs and refactors modern JavaScript using ES2023+, async/await, ESM modules and Node.js or browser APIs.