# AI-generated code debugging and code review

URL: https://byshahid.com/hire/ai-code-review-debugging/
Author: Muhammad Shahid, Senior AI Software Engineer & Full Stack Developer (https://byshahid.com/)

Your AI coding tool wrote most of the app, and now something is wrong: a bug nobody can trace, slow pages, or code you are not sure is safe. I review it, find the cause and fix it.

**Quick answer:** I debug and review code written with AI tools such as Cursor, Claude Code, Lovable, Bolt.new and GitHub Copilot: tracing bugs to their cause, fixing security issues, speeding up slow queries and APIs, and leaving tests so the fix stays fixed. I fixed random JWT logouts on a 2M+ user platform and scaled a backend from 200K to 1M+ users with about 60% faster APIs.

## What I build

- **Bug hunting:** Reproduce the problem, trace it to the cause and fix it, instead of patching symptoms the AI tool keeps reintroducing.
- **Code review:** A written review of structure, duplication, error handling and risky patterns, ranked by what matters most.
- **Security review:** Secrets, authentication, permissions, injection and dependency issues found and fixed.
- **Performance:** Slow queries, missing indexes, N+1 requests and heavy pages measured and fixed.
- **Tests:** Tests around the fixed code and the main user flows, so future AI edits do not break them again.
- **Refactoring:** Tangled AI-generated code made clear enough for you and your AI tools to keep working on.

## Results on real products

- **TheCryptoBasic:** 2M+ users — Fixed random logouts caused by JWT session bugs such as refresh races between tabs; the full write-up is on this site.
- **CV Maker – Resume Builder:** 200K → 1M+ users — Found and fixed the slow paths in a live backend: about 60% faster APIs with MongoDB indexing and Redis caching.
- **DOP:** 300M+ users — Fixed timeouts and RPC downtime in a live product used at very large scale.

## Tools I use

Cursor, Claude Code, GitHub Copilot, Lovable, Bolt.new, Node.js, TypeScript, React, Next.js, Python, MongoDB, Postgres, Redis, Jest, Playwright

## How a project works

1. **Scope call.** We talk through the goal, the current state of the product and what success looks like.
2. **Written plan.** You get fixed milestones, delivery dates and a clear price before any work starts.
3. **Build in small pieces.** I ship in small steps with regular progress updates, so you always see what is built.
4. **Tested delivery.** Delivery includes tests, documentation, handover and free support afterwards if something breaks.

## Frequently asked questions

### Can you fix bugs in code written by Cursor or Claude Code?

Yes. AI-written code is still code: I read it, reproduce the bug, find the cause and fix it in your repository.

### Why does my AI tool keep reintroducing the same bug?

Usually because the cause is elsewhere, in shared state, a race or a wrong assumption. Fixing the cause and adding a test stops the loop.

### What does an AI code review include?

A written report of bugs, security issues, performance problems and structure, ranked by risk, plus fixes for the most important items.

### Is AI-generated code safe to put in production?

It can be, after review. Common risks are exposed keys, missing permission checks, unsafe database rules and missing input validation.

### Do you work in our repository?

Yes. I work in your Git repository with small, reviewed commits or pull requests.

### Which languages and frameworks?

Mainly TypeScript and JavaScript (React, Next.js, Node.js), Python, Swift, and MongoDB, Postgres or Supabase databases.

### Can you speed up a slow app?

Yes. I measure first, then fix the real bottlenecks: queries, indexes, caching, bundle size and API design.

### Do you write tests?

Yes, around the fixed code and your main user flows, so later changes do not silently break them.

### How quickly can you start?

Usually within a day or two. Send the repository and a description of the problem for a first look.

### How is it priced?

Small fixes are hourly; a full review or larger fix is a fixed price after a first look at the code.

## Tell me what you want to build

Send the details on WhatsApp or by email: what you need, where the project is now, your deadline and budget range. You get a clear plan and price back, usually within 24 hours.

WhatsApp +92 321 7815799 · contacttoshahidkhan@gmail.com · Upwork: https://www.upwork.com/freelancers/~014a63f2391f4f4bce