performance

Performance Optimization Skill

Systematic performance analysis and optimization for RTK CLI tool, focusing on startup time (<10ms), memory usage (<5MB), and token savings (60-90%).

When to Use

• Automatically triggered: After filter changes, regex modifications, or dependency additions
• Manual invocation: When performance degradation suspected or before release
• Proactive: After any code change that could impact startup time or memory

RTK Performance Targets

Metric	Target	Verification Method	Failure Threshold
Startup time	<10ms	hyperfine 'rtk <cmd>'	>15ms = blocker
Memory usage	<5MB resident	/usr/bin/time -l rtk <cmd> (macOS)	>7MB = blocker
Token savings	60-90%	Tests with count_tokens()	<60% = blocker
Binary size	<5MB stripped	ls -lh target/release/rtk	>8MB = investigate

Performance Analysis Workflow

1. Establish Baseline

Before making any changes, capture current performance:

# Startup time baseline
hyperfine 'rtk git status' --warmup 3 --export-json /tmp/baseline_startup.json

# Memory usage baseline (macOS)
/usr/bin/time -l rtk git status 2>&1 | grep "maximum resident set size" > /tmp/baseline_memory.txt

# Memory usage baseline (Linux)
/usr/bin/time -v rtk git status 2>&1 | grep "Maximum resident set size" > /tmp/baseline_memory.txt

# Binary size baseline
ls -lh target/release/rtk | tee /tmp/baseline_binary_size.txt

2. Make Changes

Implement optimization or feature changes.

3. Rebuild and Measure

# Rebuild with optimizations
cargo build --release

# Measure startup time
hyperfine 'target/release/rtk git status' --warmup 3 --export-json /tmp/after_startup.json

# Measure memory usage
/usr/bin/time -l target/release/rtk git status 2>&1 | grep "maximum resident set size" > /tmp/after_memory.txt

# Check binary size
ls -lh target/release/rtk | tee /tmp/after_binary_size.txt