Backend Languages Pack

The problem

Shipping code with silent concurrency bugs, data races, or precision errors in financial math is easy. Standard linters catch syntax, but they often miss language-specific defense patterns like proper error wrapping in Go, event-loop blocking in Python, or floating-promise leaks in Node.js.

What it does

• Audits Go, Python, and TypeScript/Node.js source code for language-specific anti-patterns.
• Maps every identified bug to a specific file and line number to eliminate ambiguity.
• Provides full, copy-pasteable rewrites that implement defensive coding standards.
• Generates specific shell commands and test runners to verify the fix locally.
• Identifies architectural gaps like missing idempotency or incomplete error hierarchies.

Frameworks & tools

Go (1.24+), Python (3.11+), FastAPI, Pydantic, TypeScript (5+), Node.js (20+), Zod, Vitest, Pytest, and Singleflight.

Why this beats prompting it yourself

General LLMs often suggest generic fixes that ignore critical language nuances, like using floats for money or neglecting context propagation in goroutines. This skill uses a strict defense matrix that enforces specific patterns—like minor-unit integer math and exhaustive error wrapping—ensuring production-grade safety without manual oversight.

Use cases

• Reviewing concurrent Go handlers for race conditions and resource leaks.
• Hardening FastAPI routes with Pydantic validation and async-safe database calls.
• Converting Node.js Express handlers to strict TypeScript with ESM and Zod validation.
• Refactoring financial logic to use integer minor units or Decimal types instead of floats.

Known limitations

Operates strictly on source text and repository layout. It cannot compile code, execute tests, or fetch external dependencies.