Unity ECS Patterns

Production patterns for Unity's Data-Oriented Technology Stack (DOTS) including Entity Component System, Job System, and Burst Compiler.

When to Use This Skill

• Building high-performance Unity games
• Managing thousands of entities efficiently
• Implementing data-oriented game systems
• Optimizing CPU-bound game logic
• Converting OOP game code to ECS
• Using Jobs and Burst for parallelization

Core Concepts

1. ECS vs OOP

Aspect	Traditional OOP	ECS/DOTS
Data layout	Object-oriented	Data-oriented
Memory	Scattered	Contiguous
Processing	Per-object	Batched
Scaling	Poor with count	Linear scaling
Best for	Complex behaviors	Mass simulation

2. DOTS Components

Entity: Lightweight ID (no data)
Component: Pure data (no behavior)
System: Logic that processes components
World: Container for entities
Archetype: Unique combination of components
Chunk: Memory block for same-archetype entities

Detailed patterns and worked examples

Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.

Best Practices

Do's

• Use ISystem over SystemBase - Better performance
• Burst compile everything - Massive speedup
• Batch structural changes - Use ECB
• Profile with Profiler - Identify bottlenecks
• Use Aspects - Clean component grouping

Don'ts

• Don't use managed types - Breaks Burst
• Don't structural change in jobs - Use ECB
• Don't over-architect - Start simple
• Don't ignore chunk utilization - Group similar entities
• Don't forget disposal - Native collections leak