Prompt Optimizer is a multi-platform AI prompt optimization tool that helps users craft better prompts for large language models (LLMs) and image generation models. The system supports web (Vue 3 + Naive UI), desktop (Electron), Chrome extension, MCP server, and Docker deployment via a pnpm monorepo. Core workflows include system/user prompt optimization, evaluation with structured compare (pair-judge, synthesis), image generation (text2image, image2image, multi-image), variable extraction/value generation, a template system with 40+ built-in bilingual (zh/en) templates, and smart favorites with resource-aware asset management. The architecture cleanly separates framework-agnostic core services (LLM adapters, evaluation, storage, template processing) from UI composables and Electron proxies, using adapter, registry, and factory patterns extensively. A notable strength is the comprehensive test infrastructure spanning unit (Vitest), integration (real LLM API helpers gated by environment flags), and E2E (Playwright with VCR record/replay). Weaknesses include significant template duplication (bilingual files maintained separately), IPC fragility between Electron main/renderer, provider adapter maintenance overhead (16+ text adapters, 6+ image adapters), and some dead/deprecated code paths carrying legacy migration layers.