CodeMentor AI

Paste code and get a structured review back: bugs, security issues with CWE references, performance notes, an A–F grade and a refactored version in a side-by-side diff.

Role
Solo: design and build
Built
June 2026
Hosting
Vercel

Why I built it

Good code review is slow and senior engineers are busy, so a lot of code ships with blind spots nobody pointed out. I wanted that feedback loop in seconds, with no account to create.

How it works

  • Monaco, the editor behind VS Code, with seven languages. Each one loads a sample that has real problems to find.
  • A Gemini service sends the code to Gemini 2.0 Flash and exposes the review as a state stream (idle, loading, complete or error) built on an RxJS BehaviorSubject, with switchMap so a new request cancels the one in flight.
  • Results land in five tabs: Summary, Bugs, Performance, Security and Refactored Code, with severity badges and a GitHub-style diff of the refactor.
  • Every review is saved to localStorage, and the dashboard's counts are computed with Angular Signals.

Decisions and trade-offs

  • No backend. You bring your own Gemini key and it stays in your browser; without one, a mock engine returns sample reviews so the app always works.
  • Signals for synchronous UI state, RxJS for the async request flow.
  • Plain SCSS with CSS custom properties instead of a UI framework, for full control over the design system.

What's next

Streaming the review as Gemini writes it (right now the full response arrives at once), file upload, and reviewing GitHub pull requests directly.

Stack

Angular 21 (standalone) · TypeScript · RxJS · Angular Signals · Monaco Editor · Gemini 2.0 Flash API · SCSS