State Management in Angular: Options and Tradeoffs

State management becomes important when your app grows beyond a few components.

## Levels of state (professional view)

### 1) Local component state
Best for:
- toggles, dropdowns, UI selection
Tools:
- component properties
- Signals

### 2) Shared app state (feature-level)
Best for:
- logged-in user profile
- shopping cart
- filters shared across pages
Tools:
- a shared service with Signals
- BehaviorSubject pattern

### 3) Global enterprise state
Best for:
- huge apps with many teams
- strict patterns and dev tooling
Tools:
- NgRx (actions, reducers, effects)

## Quick decision chart

```mermaid
flowchart TD
  A[Need shared state?] -->|No| B[Use local Signals]
  A -->|Yes| C[Is it a big multi-team app?]
  C -->|No| D[Signals Store Service]
  C -->|Yes| E[NgRx or equivalent]
```

## Key idea

Do not over-engineer early. Start simple, scale when pain appears.

> Next: Build a simple Signals-based store service step by step.