name: axiom-ios-performance description: Use when app feels slow, memory grows, battery drains, or diagnosing ANY performance issue. Covers memory leaks, profiling, Instruments workflows, retain cycles, performance optimization.

iOS Performance Router

You MUST use this skill for ANY performance issue including memory leaks, slow execution, battery drain, or profiling.

When to Use

Use this router when:

• App feels slow or laggy
• Memory usage grows over time
• Battery drains quickly
• Device gets hot during use
• High energy usage in Battery Settings
• Diagnosing performance with Instruments
• Memory leaks or retain cycles
• App crashes with memory warnings

Routing Logic

Memory Issues

Memory leaks (Swift) → /skill axiom-memory-debugging

• Systematic leak diagnosis
• 5 common leak patterns
• Instruments workflows
• deinit not called

Memory leaks (Objective-C blocks) → /skill axiom-objc-block-retain-cycles

• Block retain cycles
• Weak-strong pattern
• Network callback leaks

Performance Profiling

Performance profiling → /skill axiom-performance-profiling

• Time Profiler (CPU)
• Allocations (memory growth)
• Core Data profiling (N+1 queries)
• Decision trees for tool selection

Energy Issues

Battery drain, axiom-high energy → /skill axiom-energy

• Power Profiler workflow
• Subsystem diagnosis (CPU/GPU/Network/Location/Display)
• Anti-pattern fixes
• Background execution optimization

Symptom-based diagnosis → /skill axiom-energy-diag

• "App at top of Battery Settings"
• "Device gets hot"
• "Background battery drain"
• Time-cost analysis for each path

API reference with code → /skill axiom-energy-ref

• Complete WWDC code examples
• Timer, network, location efficiency
• BGContinuedProcessingTask (iOS 26)
• MetricKit setup

Decision Tree

User reports performance issue
  ├─ Memory?
  │  ├─ Swift code? → memory-debugging
  │  └─ Objective-C blocks? → objc-block-retain-cycles
  │
  ├─ Energy/Battery?
  │  ├─ Know the symptom? → energy-diag
  │  ├─ Need API reference? → energy-ref
  │  └─ General battery drain? → energy
  │
  ├─ Want to profile?
  │  └─ YES → performance-profiling
  │
  └─ General slow/lag? → performance-profiling

Critical Patterns

Memory Debugging (memory-debugging):

• 6 leak patterns: timers, observers, closures, delegates, view callbacks, PhotoKit
• Instruments workflows
• Leak vs caching distinction

Performance Profiling (performance-profiling):

• Time Profiler for CPU bottlenecks
• Allocations for memory growth
• Core Data SQL logging for N+1 queries
• Self Time vs Total Time

Energy Optimization (energy):

• Power Profiler subsystem diagnosis
• 8 anti-patterns: timers, polling, location, animations, background, network, GPU, disk
• Audit checklists by subsystem
• Pressure scenarios for deadline resistance

Example Invocations

User: "My app's memory usage keeps growing" → Invoke: /skill axiom-memory-debugging

User: "I have a memory leak but deinit isn't being called" → Invoke: /skill axiom-memory-debugging

User: "My app feels slow, where do I start?" → Invoke: /skill axiom-performance-profiling

User: "My Objective-C block callback is leaking" → Invoke: /skill axiom-objc-block-retain-cycles

User: "My app drains battery quickly" → Invoke: /skill axiom-energy

User: "Users say the device gets hot when using my app" → Invoke: /skill axiom-energy-diag

User: "What's the best way to implement location tracking efficiently?" → Invoke: /skill axiom-energy-ref