---
name: python-performance-adrs
description: >
  Python performance ADRs and rules.
  Load this when writing or refactoring performance-sensitive Python code
  (CLI tools, data pipelines, DB/async boundaries, JSON, etc.).
---

# Python Performance ADRs (Skill)

Use this skill when:
- Implementing new Python components.
- Refactoring hot paths, imports, async boundaries.
- Touching JSON, DB, collections, string formatting, or error handling.

## How to use

1) Always load:
   - RULEBOOK.md (concise rules, always valid)
2) For deeper context, load only the relevant paper:
   - papers/async-overhead.md
   - papers/collection-membership.md
   - papers/json-serialization.md
   - papers/exception-flow.md
   - papers/string-formatting.md
   - papers/memory-slots.md
   - papers/import-optimization.md
   - papers/database-patterns.md

## Rules (summary)

- Prefer sync over async unless you truly need concurrency.
- Use sets for membership checks on large collections.
- Use orjson for high-volume JSON where possible.
- Avoid expensive exception paths in hot loops.
- Use f-strings for formatting.
- Use __slots__ in high-volume objects.
- Be cautious with many imports in CLI / startup paths.
- Treat SQLite writes as a potential bottleneck.

All details are enforced via RULEBOOK.md; never reinvent these patterns.