Design Pattern Interview Preparation Sheet – Master the Core of System Design
If you are preparing for system design or low-level design interviews, especially at product-based companies or FAANG , this sheet is made just for you.
We have listed all 23 essential Design Patterns (from the Gang of Four), categorized by difficulty (Easy, Medium, Hard), and crafted a system to help you track your progress, reflect with notes, and actively learn.
What makes this sheet special?
- Progress Tracker – Mark each pattern as "Done" after you’ve studied it. See your progress at a glance.
- Personal Notes – Add your own notes for revision. Write down insights, examples or things to revisit.
- Think Before You See the Solution – Each pattern comes with a hint section to help you think through the problem before jumping into the implementation. This boosts your problem-solving skills and helps you internalize the concept.
- Links – Practice problems and reference material (optional) to go deeper when needed.
- Categorized by Difficulty – Start easy, build confidence and work your way up to advanced patterns.
Total Progress
0 / 23
Easy
0 / 6
Medium
0 / 12
Hard
0 / 5
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Why Use This Design Pattern Sheet
Design patterns are essential for writing scalable, maintainable and modular code. This sheet brings together all 23 Gang of Four (GoF) design patterns in one place with clear descriptions, difficulty levels, hints and tracking features.
Instead of just memorizing pattern names, this sheet encourages you to understand their intent, structure and real-world application which is exactly what interviewers look for in system design and low-level design interviews.
How This Sheet Helps in Interview Preparation
- Covers all core GoF design patterns with clear intent and usage examples.
- Patterns categorized by difficulty help you build confidence gradually.
- Practice hints encourage critical thinking before viewing solutions.
- Progress tracking helps you stay consistent and see your improvement.
- Notes section lets you capture insights, alternatives and personal learning points.
By using this sheet consistently, you can confidently discuss design patterns during interviews, apply them in real coding scenarios and bridge the gap between theoretical knowledge and practical application.
How to Use This Sheet
- Start with the easier patterns to build fundamental understanding.
- For each pattern, read the intent, problem statement and hint before looking at example code.
- Attempt to implement the pattern in your preferred language this deepens retention.
- Write personal notes on nuances, trade-offs and real use cases for each pattern.
- Mark patterns as completed only when you can explain them logically to someone else.
Review regularly , design patterns become more intuitive with repeated exposure and implementation.
Who Can Use This Sheet
- Students preparing for software engineering interviews.
- Developers targeting product-based companies or FAANG roles.
- Professionals brushing up on system and object-oriented design knowledge.
- Engineers looking to improve code quality through well-structured design.
This sheet is suitable for both beginners who want a guided learning path and experienced developers seeking a solid revision resource.
Frequently Asked Questions (FAQ)
1. Why are design patterns asked in interviews?
Design patterns show your ability to structure code and solve recurring architectural problems. They are a key part of low-level and system design interview evaluations.
2. Do I need to memorise all patterns?
No, it’s more important to understand the intent, use cases and trade-offs of patterns instead of rote memorisation.
3. Which patterns are commonly asked?
Patterns like Singleton, Factory Method, Strategy, Observer and Decorator are frequently discussed due to their frequent use in real projects.
4. Can I practise these patterns in any language?
Yes, patterns are conceptual and can be implemented in languages like Java, C++, Python and JavaScript.
5. How long does it take to master design patterns?
Time varies based on experience, but consistent study and implementation over a few weeks can prepare you well for interviews.