Crush Your System Design Interview: Tips and Techniques

Crush Your System Design Interview: Tips and Techniques

"Spiral Approach vs. Incremental MVP: System Design Interview Strategies"

Hey there, tech enthusiasts! I'm Gaurav, and I'm really into system design. I love tackling those tough technical puzzles. Whether you're just starting or you've been around the block, I'm here to help you understand system design interviews.

I've spent a lot of time figuring out how to build big, powerful digital systems. And guess what? I've had my share of system design interviews. Today, I'm excited to guide you through these interviews and share tips and tricks to make you feel confident.

In this blog post, we're going to talk about how to start right with system design interviews. We'll use two cool methods: the Spiral Approach and Incremental MVP (don't worry, they're not as complicated as they sound). I'll explain them in simple terms, with examples, so you can use them too.

Whether you're a newbie taking your first steps into system design interviews or you want to level up your skills, this post is for you. Together, we'll break down the secrets to nailing system design interviews, step by step.

So, let's jump into the world of system design interviews. Ready? Let's roll!

In the world of tech and creating new things, we often face tricky challenges. Think of building cool apps or products. But don't worry, there are smart ways to tackle these challenges, and today, we'll talk about two of them: Incremental MVP and the Spiral Approach.

Now, these might sound a bit fancy, but don't be scared. We're going to break them down so that everyone can understand, no matter if you're a tech wizard or just curious. Whether you have a big idea or want to make your projects work better, these approaches can help you a lot.

So, let's dive in and discover how Incremental MVP and the Spiral Approach can make your projects easier, simpler, and more successful.

Right Start Approach for System Design Interviews:

1. Understand the Problem (Spiral Approach - Planning Phase): Begin by thoroughly understanding the problem statement given by the interviewer. Ask clarifying questions to make sure you have a clear picture of what needs to be designed.

2. Identify the Core Features (Incremental MVP - Start with a Simple MVP): Determine the essential features or components required to solve the problem. Focus on the basics initially to build a solid foundation.

3. Outline the High-Level Design (Spiral Approach - Planning Phase): Start by sketching a high-level design of the system. This can be a simple diagram or a written description that shows how the different components will interact.

4. Prioritize (Incremental MVP - Release Early): Decide which core features to implement first. Prioritize them based on their importance and feasibility. What features can you include in the initial version to make it functional?

5. Build and Explain (Spiral Approach - Engineering Phase): Begin explaining your design incrementally, starting with the most critical components. Describe how each component works and how it interacts with others. As you explain, focus on the core features you've prioritized.

6. Gather Feedback (Incremental MVP - Listen to User Feedback): Invite the interviewer to provide feedback on the design you've presented so far. Be open to their suggestions and questions. This is like releasing your initial version and collecting feedback.

7. Adapt and Iterate (Spiral Approach - Evaluation and Planning for the Next Iteration): Based on the feedback and questions, be ready to adapt and refine your design. Consider how you can improve or address any concerns. This mirrors the iterative process of refining your product.

8. Continue Explaining (Incremental MVP - Iterate): Keep explaining your design, incrementally adding more details and components. As you progress, refer back to the feedback you received earlier to show how you've incorporated it.

9. Handle Edge Cases (Spiral Approach - Risk Analysis): Address potential edge cases and risks in your design. Think about how your system will handle unusual situations or scenarios that weren't initially considered.

10. Summarize (Spiral Approach - Evaluation and Planning for the Next Iteration): Summarize your design, emphasizing how it addresses the problem statement and satisfies the requirements. Highlight any major improvements or changes made based on feedback.

11. Conclusion (Incremental MVP - Keep It Simple): Conclude the interview confidently, emphasizing that you've focused on delivering a functional and simple solution that can be improved and expanded over time.

Remember, the key is to show a structured approach to system design, gradually building your solution while considering feedback and making adjustments. This demonstrates your ability to think systematically, prioritize effectively, and adapt to changing requirements – all crucial skills in system design interviews.

"Spiral Approach: Scaling Success Step by Step"

The Spiral Model is an iterative and incremental approach to system design and development. It was first introduced by Barry Boehm in 1986 and is often used in software engineering, but its principles can be applied to system design more broadly. The Spiral Model is especially useful when dealing with complex and large-scale projects where uncertainty and risk need to be managed effectively. It combines elements of both iterative and incremental development processes and incorporates a risk-driven approach.

The Spiral Model consists of a series of repeating cycles, or spirals, each of which represents a phase in the development process. These phases are typically as follows:

  1. Planning: In this phase, project objectives, constraints, and requirements are gathered and analyzed. The project's scope, budget, and schedule are defined. Key risks are identified, and a plan is developed to manage them.

  2. Risk Analysis: This phase focuses on assessing and mitigating risks associated with the project. Risk analysis involves identifying potential risks and their potential impact on the project's success. Strategies are formulated to address these risks effectively.

  3. Engineering: During this phase, the actual development of the system or product takes place. The engineering phase can be broken down into smaller iterations or increments, depending on the project's complexity. Each iteration produces a partial version of the system that is tested and integrated.

  4. Evaluation: After each iteration, the product is evaluated to ensure that it meets the specified requirements and quality standards. This evaluation can include testing, user feedback, and reviews.

  5. Planning for the Next Iteration: Based on the evaluation of the current iteration, plans are made for the next iteration. Changes and improvements are proposed, and the project plan is adjusted accordingly. If risks have evolved, their mitigation strategies may also need to be updated.

The key characteristics of the Spiral Model include:

  • Iterative: The process goes through multiple iterations, with each iteration refining the product further.

  • Incremental: The product is built incrementally, with new features and functionality added in each iteration.

  • Risk-Driven: The model places a strong emphasis on risk management. Risks are assessed and addressed throughout the project's lifecycle.

  • Flexibility: The model allows for changes in project requirements and design based on lessons learned from previous iterations.

  • Client Involvement: Clients or stakeholders are involved in the evaluation process and can provide feedback that influences the direction of the project.

  • Phases Overlapping: Phases of the spiral can overlap to some extent, which can accelerate the development process.

The Spiral Model is well-suited for projects with evolving or unclear requirements, as it allows for flexibility and adaptation as the project progresses. However, it can also be more resource-intensive compared to other development models due to the need for frequent iterations and evaluations.

It's essential to note that the number of spirals and the specific activities within each spiral can vary depending on the project's unique characteristics and requirements. The model is highly customizable to fit the needs of different projects.

"Incremental MVP: Building Big Success, One Step at a Time"

An Incremental MVP (Minimum Viable Product) is an approach to developing a product or system where you build and release the MVP in multiple, smaller increments rather than delivering it all at once. This approach allows you to quickly release a basic version of your product to start gathering user feedback and validating your assumptions while continuously adding new features and improvements in subsequent iterations. Here's a deeper explanation of Incremental MVP:

  1. Minimum Viable Product (MVP): The concept of an MVP involves creating a minimal version of your product that contains only the essential features required to solve a specific problem or deliver value to your target audience. The MVP is designed to be functional, but it may lack certain advanced features or enhancements. Its primary purpose is to test your product idea and gather real-world feedback.

  2. Incremental Development: With the Incremental MVP approach, instead of trying to build a complete MVP with all the envisioned features, you break down the MVP into smaller, manageable increments. Each increment represents a subset of features or functionality that can be developed and released independently.

  3. Release Early and Often: The key principle behind Incremental MVP is to release these smaller increments to your users as soon as they are ready. This means that you don't wait until the entire MVP is fully developed before releasing it. Instead, you release the first increment, gather feedback, make improvements, and then release the next increment. This process continues iteratively.

  4. Feedback-Driven Development: Gathering user feedback is a central element of this approach. By releasing increments and collecting feedback from real users, you can make data-driven decisions about what features to prioritize and how to enhance your product. This feedback loop helps you validate assumptions, identify pain points, and make necessary adjustments.

  5. Iterative Refinement: As you receive feedback and insights from users, you use this information to refine your product in subsequent increments. You can add new features, improve existing ones, and address any issues or concerns raised by users. This iterative refinement process continues until you reach a point where your product meets the needs and expectations of your target audience.

  6. Faster Time-to-Market: Incremental MVP allows you to get your product to market faster compared to building a fully-featured MVP. This speed can be crucial in competitive markets and can help you establish your presence sooner.

  7. Risk Mitigation: By releasing smaller increments and gathering feedback early, you can identify and address potential problems or market-fit issues at an earlier stage. This reduces the risk of investing significant resources into a product that may not resonate with users.

  8. Scalability: The incremental approach can also be more scalable from a development perspective. It allows you to allocate resources more efficiently, focusing on the most critical features first and gradually expanding the product's capabilities.

In summary, Incremental MVP is a strategic approach to product development that emphasizes releasing smaller, functional increments of your MVP to gather feedback, validate your assumptions, and refine your product over time. It enables a more flexible and adaptive development process, reducing the time and resources required to bring your product to market while ensuring it aligns with user needs and expectations.

Let's break down the descriptions of Incremental MVP and Spiral Approach in simple language:

Incremental MVP (Minimum Viable Product):

Description: Incremental MVP is like building a puzzle one piece at a time. Imagine you want to make a cool video game. Instead of trying to create the entire game at once, you start with the most basic version. This might include a character that can move around and jump but doesn't do much else.

Approach: Then, you show this basic version to people (like your friends or testers) to see if they like it. They might say, "Hey, it would be even cooler if the character could shoot lasers!" So, you add that feature in the next version. You keep doing this, adding new stuff in small steps, until your game becomes awesome.

Why It's Cool: Incremental MVP helps you make a good product without spending too much time on things people might not even want. You start simply and add what's needed based on feedback.


Spiral Approach:

Description: The Spiral Approach is like climbing a mountain while checking for safety at each step. Think of creating a new app, like a messaging app.

Approach: First, you make a plan. You think about what your System needs /functional and non functional needs, like sending and receiving messages. Then, you look for potential problems, like what if someone sends a million messages at once? You figure out ways to handle these issues.

Next Steps: Now, you start building your app. But you don't build everything at once. You make a basic version first, like just sending text messages. You test it to make sure it works well and is safe.

Repeating the Process: As you keep improving, you add more features, like sending images or videos. You also keep checking for new problems and making your app better and safer.

Why It's Cool: The Spiral Approach keeps you from running into big problems later. It's like taking small steps and being safe while climbing a mountain.


Both Incremental MVP and the Spiral Approach are smart ways to make things – whether it's a game, an app, or something else – step by step, without getting overwhelmed. You start simple, learn from what you do, and make it better over time.

Here are some useful resources to help you build a strong foundation for system design interviews, along with links:

  1. System Design Interview - An Insider's Guide (Alex Xu): key system design concepts and provides valuable tips. System Design Interview - An Insider's Guide.

  2. System Design Interviews (HiredInTech): A free platform that offers practice questions and solutions for system design interviews. System Design Interviews

  3. Designing Data-Intensive Applications (Book by Martin Kleppmann): This book dives deep into the principles, practices, and trade-offs in designing data-intensive applications. Designing Data-Intensive Applications

  4. System Design Primer (GitHub Repository): A comprehensive collection of resources, including articles, books, videos, and sample questions, compiled on GitHub. System Design Primer

  5. YouTube Channels: There are several YouTube channels that offer valuable insights into system design, such as "Tech Dummies," "The Net Ninja," and "Academind", "Gaurav Sen", "Byte Byte go", "Asli Engineering by Arpit Bhayani".

  6. System Design Interview Questions on Glassdoor: Real interview questions from companies like Facebook, Google, and Amazon, along with answers and insights. Glassdoor System Design Interviews

These resources cover a wide range of topics related to system design interviews, from foundational knowledge to practical examples. Feel free to explore them to build a strong foundation and enhance your system design skills.

System Design is All about Tread off

system design is indeed all about trade-offs. In the process of designing complex systems, engineers and architects are constantly making decisions that involve trade-offs between various factors. Here are some key trade-offs that often come into play in system design:

  1. Performance vs. Cost: You can optimize performance by using powerful, expensive hardware, but this increases costs. Striking the right balance between performance and cost is crucial.

  2. Scalability vs. Complexity: Designing a highly scalable system often requires adding complexity. You must decide how much complexity is justified by the need for scalability.

  3. Consistency vs. Availability: Ensuring data consistency across a distributed system can impact system availability. Striking a balance between the two is essential.

  4. Latency vs. Throughput: Reducing latency (the time it takes for a single operation) can sometimes decrease overall throughput (the number of operations per second). It's essential to find the right trade-off depending on the system's use case.

  5. Data Storage vs. Data Processing: Storing a vast amount of data may be necessary for analysis but can be expensive. Deciding how much data to store and how much to process in real-time is a trade-off.

  6. Ease of Maintenance vs. Performance: Complex systems can be harder to maintain. Deciding on the level of complexity while considering future maintenance needs is crucial.

  7. Security vs. Usability: Adding layers of security can make a system more secure but less user-friendly. Finding the right balance is essential, depending on the application and user base.

  8. Consistency Models: In distributed systems, choosing a consistency model (e.g., strong consistency, eventual consistency) involves trade-offs between data accuracy and system responsiveness.

  9. Redundancy vs. Cost: Adding redundancy in the form of backup servers or data centers improves system reliability but increases costs.

  10. Ease of Development vs. Performance: Frameworks or tools that simplify development may introduce performance overhead. Deciding when to use them depends on project priorities.

System designers need to carefully evaluate these trade-offs based on the specific requirements of the project, the available resources, and the expected usage patterns. Making informed decisions in these trade-offs is a fundamental aspect of effective system design.

Design System with effective Cost Managment Strategy

Cost management is an essential aspect of system design interviews, especially when the interviewer specifically asks you to consider cost. Here's why cost management is important in these interviews:

  1. Real-World Relevance: In actual software development and system design projects, cost is a critical factor. Companies need to optimize their resources to ensure profitability and sustainability. Therefore, interviewers often test candidates on their ability to make cost-effective design decisions.

  2. Trade-offs: Cost is often linked to trade-offs in system design. For example, using high-end servers might enhance performance but also increase infrastructure costs. Your ability to balance performance, scalability, and cost can demonstrate your design maturity.

  3. Efficiency: Cost-effective solutions are typically more efficient. Designing a system that minimizes resource usage, whether it's computing power, storage, or network bandwidth, can lead to significant savings.

  4. Scalability: Cost considerations are closely tied to system scalability. A well-designed system should scale efficiently without incurring excessive costs. Interviewers may want to see how you plan for cost-effective scaling.

  5. Competitive Advantage: Companies that can deliver high-quality services while managing costs effectively gain a competitive advantage. Demonstrating cost-consciousness can be seen as an asset.

  6. Business Impact: Design decisions can have a direct impact on a company's bottom line. By considering cost, you show your awareness of the broader business implications of your design choices.

  7. Resource Allocation: Cost management involves deciding where to allocate resources. This includes choosing between different database solutions, cloud providers, server configurations, and more. Your choices can significantly impact on the budget.

  8. Budget Constraints: Many real-world projects have budget constraints. Interviewers may present you with a scenario where you must design within a limited budget, testing your ability to prioritize and allocate resources effectively.

In summary, cost management is vital in system design interviews because it reflects the practicality and real-world applicability of your designs. Demonstrating your ability to make cost-effective decisions, consider trade-offs, and optimize resource usage can impress interviewers and showcase your ability to design systems that are both technically sound and financially responsible.

general behavior during system design interview and some tips to crack them

Behavior during a system design interview is crucial, as it's not only about technical knowledge but also your problem-solving skills, communication, and collaboration. Here are some general behavioral tips to excel in system design interviews:

  1. Listen Actively: Pay close attention to the interviewer's problem statement and requirements. Make sure you understand the constraints and objectives before diving into the design.

  2. Ask Clarifying Questions: Don't hesitate to seek clarification if anything is unclear. It's better to ask questions at the beginning than to make incorrect assumptions.

  3. Think Aloud: As you work through the design, verbalize your thought process. Explain your reasoning, trade-offs, and decisions. This helps the interviewer understand your approach.

  4. Break Down the Problem: Divide the problem into smaller, manageable parts. Start with the most critical components and gradually build up the entire system.

  5. Prioritize and Justify: Prioritize features or components based on importance and complexity. Explain why you're tackling certain parts first and how they contribute to the overall design.

  6. Use Real-World Examples: Draw parallels with real-world systems or applications you're familiar with. This can help you explain your design choices more effectively.

  7. Consider Trade-offs: Be prepared to discuss trade-offs, such as scalability vs. simplicity, consistency vs. availability, and performance vs. cost. Justify your choices.

  8. Write Clean Code: If you're asked to write code, keep it neat, well-structured, and easy to read. Use meaningful variable names and follow best coding practices.

  9. Stay Calm Under Pressure: System design interviews can be challenging. Stay composed, even if you encounter difficulties. Don't be afraid to admit when you're uncertain about something.

  10. Emphasize Communication: Communication skills are vital. Clearly and concisely explain your design, using diagrams or visual aids when appropriate. Encourage a two-way conversation with the interviewer.

  11. Practice Whiteboarding: If possible, practice system design interviews on a whiteboard or a virtual whiteboard tool. This can help you get used to sketching diagrams and explaining your ideas in a visual format.

  12. Time Management: Keep an eye on the time. System design interviews can be time-limited, so manage your time wisely to cover the most critical aspects of your design.

  13. Learn from Feedback: Be open to feedback from the interviewer. If they suggest improvements or ask you to reconsider certain aspects of your design, take it as an opportunity to learn and adapt.

  14. Stay Updated: Continuously improve your knowledge of system design principles and best practices. Stay informed about industry trends and emerging technologies.

Remember that practice is key to success in system design interviews. You can improve your skills by practicing with mock interviews, reading case studies, and seeking feedback from peers or mentors. Additionally, reviewing and learning from your mistakes in past interviews can help you refine your approach.

Overall, a combination of technical knowledge, problem-solving skills, effective communication, and a calm demeanor can help you excel in system design interviews and increase your chances of success.

Conclusion: -

System design interviews are a fascinating journey into the world of creating efficient, scalable, and cost-effective solutions. In this blog post, we've explored two powerful approaches, the Spiral Approach and Incremental MVP, simplifying these complex concepts to help you tackle system design interviews with confidence.

Remember, the right start approach involves understanding the problem, breaking it down into manageable parts, and gradually building a robust solution. The Spiral Approach encourages iterative refinement, just like climbing a mountain while ensuring safety at each step. Incremental MVP helps you create a minimum viable version and incrementally improve it based on feedback.

As you embark on your system design interview journey, keep these approaches in mind. They'll not only help you with interviews but also with real-world projects. So, whether you're a beginner venturing into the world of system design or a seasoned pro looking to enhance your skills, we hope this guide serves as a valuable resource.

We've delved into the world of system design interviews, making complex concepts accessible to everyone. We've explored the Spiral Approach and Incremental MVP, two smart strategies to tackle system design challenges effectively.

We've broken down these approaches into simple, practical steps, providing you with insights, examples, and tips to approach system design interviews with confidence. Whether you're new to system design or seeking to enhance your skills, this guide is designed to cater to your needs

If you find this guide helpful and want to stay updated on the latest insights and resources in system design and tech, let's connect on LinkedIn! Click to connect, and let's continue the conversation.

We look forward to connecting with fellow tech enthusiasts and sharing knowledge in the exciting world of system design and technology. See you on LinkedIn!

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