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name: optimization-techniques description: Performance optimization strategies. Use ONLY after profiling identifies bottlenecks.

Optimization Techniques Skill

Performance optimization strategies for Go. ONLY use after profiling!

When to Use

Use ONLY after profiling identifies actual bottlenecks. NEVER optimize prematurely (KISS principle).

Pre-allocate Slices

Copy// Good - pre-allocate when size known
items := make([]Item, 0, expectedSize)

// Bad - repeated allocations
var items []Item

Use strings.Builder

Copy// Good
var b strings.Builder
for _, s := range strings {
    b.WriteString(s)
}
result := b.String()

// Bad - repeated allocations
result := ""
for _, s := range strings {
    result += s
}

sync.Pool for Reusable Objects

Copyvar bufferPool = sync.Pool{
    New: func() interface{} {
        return new(bytes.Buffer)
    },
}

buf := bufferPool.Get().(*bytes.Buffer)
defer bufferPool.Put(buf)
buf.Reset()
// use buf

Minimize Allocations

Copy// Good - reuse buffer
buf := make([]byte, 1024)
for {
    n, _ := r.Read(buf)
    process(buf[:n])
}

// Bad - allocate each time
for {
    buf := make([]byte, 1024)
    n, _ := r.Read(buf)
    process(buf[:n])
}

Golden Rules

1. Profile first - Don't guess
2. Measure impact - Benchmark before/after
3. KISS principle - Simple first, optimize later
4. Maintain readability - Don't sacrifice clarity
5. Focus on hot paths - 80/20 rule