Why this matters
- Package layout — detailed pointwise breakdown in the section below.
- Interface extraction — detailed pointwise breakdown in the section below.
- Skeleton code — detailed pointwise breakdown in the section below.
- Time boxing — detailed pointwise breakdown in the section below.
- Whiteboard clarity often decides pass/fail before code depth.
1. ClarifyRequirements + scope
2. EntitiesNouns, verbs, ownership
3. APIsPublic operations
4. Class diagramRelationships
5. PatternsWhere they earn their keep
6. CodeCore paths + edge cases
Overview
Translate diagrams into packages and interfaces without over-engineering. Study each section below in order — every list is interview-ready reference material.
Package layout
Points to cover
- Definition — what Package layout means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
Interface extraction
Points to cover
- Definition — what Interface extraction means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
Skeleton code
Points to cover
- Definition — what Skeleton code means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
Time boxing
Points to cover
- Definition — what Time boxing means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
// CampusOS — apply "Package layout" on paper first, then in code
public final class WhiteboardToCodeExample {
// 1. Name entities from the problem statement
// 2. Draw relationships before writing methods
// 3. Introduce patterns only when a force appears
}
Quick recall
Everything you need if you only revisit this box.
- Package layout — review this slice before mock interviews.
- Interface extraction — review this slice before mock interviews.
- Skeleton code — review this slice before mock interviews.
- Time boxing — review this slice before mock interviews.
Test yourself
Answer these before moving on — recall is what makes it stick.