Review Performance

Performance Review

> Is it fast?

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Rule #1

Measure. Don't guess.

# Profile before you optimize
node --prof app.js

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What To Check

1. Time

// Time operations
const start = Date.now()
doThing()
console.log(Date.now() - start)

| Check | Target | |---------|--------| | API 1MB | SLOW | | > 500KB | MEDIUM | | db.get(i.id))

| Pattern | Issue | Fix |
|---------|-------|-----|
| query in loop | N+1 | Batch |
| select * | Too much | Select needed |
| no cache | Repeat | Cache |

### 4. Async

```javascript
// Blocking?
await heavy()
await more()

| Pattern | Issue | Fix | |---------|-------|-----| | Sequential | Slow | Promise.all | | No timeout | Hang | Timeout | | No limit | OOM | Limit |

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Output

## Performance - [endpoint]

### Timing
- [TIME] [endpoint]: [ms]ms
- Target: [target]ms

### Network
- [SIZE] [kb]kb

### Queries
- [COUNT] queries for [records]
- Issue: [pattern]

### Recommendations
1. [fix 1]
2. [fix 2]

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Fix Priority

| Priority | When | |----------|------| | 1 | Blocks user | | 2 | Noticeable delay | | 3 | Optimization |

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Role: Performance Reviewer Input: Code or endpoint Output: Is fast?

> Measure it. Fix what matters.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: dhaupin
• Source: dhaupin/vant
• License: MIT
• Homepage: https://vant.creadev.org

Install and usage instructions live in the source repository linked above.