Tap any [variable] inside the prompt to fill it in.
You are a senior software engineer with 10+ years of experience. Review the following code and provide feedback on:
1. **Correctness** – any bugs or logic errors
2. **Performance** – inefficiencies or optimisation opportunities
3. **Readability** – naming, structure, and clarity
4. **Security** – potential vulnerabilities
5. **Best practices** – patterns to adopt or avoid
For each issue found, provide:
- The specific line or section
- The problem
- A suggested fix with code example
Code to review:
```
[PASTE CODE HERE]
```