During a Systems design interview, we have approximately 45 minutes to design an entire system. Obviously, it’s impossible to design a system in depth. Instead, we need to think about the system at a high level.
We also have to make specific questions assuming we will have only the essencial features without too much complexity, otherwise, it will be impossible to even complete the design.
With that in mind let’s see what questions we should make, how to design a high-level Amazon e-commerce, the database model so that we know better what to do in such interview.
Ask clarifying questions
When designing an Amazon-like e-commerce system for a systems design interview, you can ask the following clarifying questions to gather more information and understand the requirements:
Expected User Base: What is the expected number of concurrent users and daily active users? Understanding the scale of the system will help determine the required infrastructure and scalability considerations.
Geographical Scope: Is the e-commerce platform targeting a specific region or operating globally? This will impact decisions related to language support, currency conversion, and content delivery.
Product Diversity: What types of products will be sold on the platform? Are they physical goods, digital products, or both? The nature of the products will influence the system’s handling of inventory, shipping, and fulfillment.
Third-Party Sellers: Will the platform allow third-party sellers to offer their products? If yes, what are the requirements for onboarding and managing these sellers? This will affect the system’s architecture, user management, and payment processing.
Availability and Performance: What are the desired availability and performance targets for the system? Is there a specific service level agreement (SLA) to meet? This information will guide decisions related to redundancy, load balancing, and caching.
Security Considerations: What security measures should be implemented to protect user data, prevent unauthorized access, and secure transactions? Understanding the desired security level will influence decisions related to authentication, authorization, and data encryption.
Payment Methods: What payment methods will be supported? Will the system integrate with various payment gateways or use a custom payment processing solution? This will impact the payment gateway integration and the handling of financial transactions.
Mobile Support: Will the system require a dedicated mobile application or have responsive web design for mobile devices? Understanding the mobile requirements will influence decisions related to user interface design and API development.
Personalization and Recommendations: Will the system provide personalized product recommendations based on user behavior and preferences? Understanding the need for personalization will influence decisions related to user profiling, recommendation algorithms, and data storage.
Internationalization and Localization: Will the system support multiple languages, currencies, and regional preferences? This will impact decisions related to content management, localization of product information, and international shipping.
Analytics and Reporting: What types of analytics and reporting capabilities are required? Are there any specific metrics or performance indicators that need to be tracked? Understanding the reporting needs will guide decisions related to data collection, storage, and analysis.
Remember, these questions are just a starting point, and the interviewer may provide additional context or constraints that will inform your design further.
DB Model Design
Before designing our DB model, we must keep in mind that we won’t be able to design a very robust DB model. The following model is a simplified version with the essencial tables for essential features:
Highlevel Systems design
Designing an Amazon-like e-commerce system for a systems design interview requires careful consideration of various components and their interactions. Here’s a high-level overview of the system architecture:
Client Interface: Users interact with the system through a web or mobile interface. The interface allows them to search for products, view product details, add items to their cart, and proceed to checkout.
Load Balancer: Incoming requests from clients are distributed across multiple web servers using a load balancer. The load balancer ensures optimal resource utilization and high availability.
Web Servers: The web servers handle client requests and generate dynamic web pages. These servers communicate with other components to fetch product information, user data, and process transactions.
Product Catalog: The product catalog stores information about the available products. It includes details like product name, description, price, images, and other attributes. The catalog can be stored in a relational database or a NoSQL store for scalability.
User Management: The system manages user accounts, authentication, and authorization. User information such as names, addresses, and payment methods can be stored in a user database. Authentication mechanisms like OAuth or JSON Web Tokens (JWT) can be used to secure user sessions.
Shopping Cart: The shopping cart holds the selected items for each user during their shopping session. It can be implemented using a combination of server-side and client-side storage mechanisms like cookies or sessions.
Order Processing: When a user checks out, the system processes the order. It verifies the availability of items, calculates the total cost, and generates an order confirmation. The order details are stored in the database, and inventory is updated accordingly.
Payment Gateway: The payment gateway handles payment processing. It securely communicates with external payment providers to authorize and process credit card transactions or other payment methods.
Inventory Management: The inventory management system tracks the availability of products. It ensures that products are not oversold and updates the inventory as orders are placed or canceled. Inventory can be stored in a separate database or integrated with the product catalog.
Reviews and Ratings: Users can provide reviews and ratings for products. The system stores this information and displays it on the product details page.
Caching and Content Delivery: To improve performance, caching mechanisms like Content Delivery Networks (CDNs) can be used to cache static content such as product images, CSS, and JavaScript files. This reduces the load on the web servers and improves response times.
Analytics and Monitoring: The system collects data on user interactions, sales, and performance metrics. This data can be used for generating reports, monitoring system health, and making data-driven decisions.
Search Functionality: An efficient search mechanism is crucial for an e-commerce system. Implementing a search engine or utilizing search platforms like Elasticsearch can help provide fast and accurate search results.
It is important to note that this is a high-level overview, and the actual implementation details would require more in-depth analysis and consideration of specific requirements and constraints.
Conclusion
This should be enough for a Systems design interview. Of course, you will have to go with the flow of the interview but the base design for Amazon e-commerce is what we discussed.
Now, let’s see the most important points to get prepared for the systems design interview. The same principles to design Amazon e-commerce are applied for other systems. Let’s recap them:
- Designing an Amazon-like e-commerce system requires careful consideration of various components and their interactions.
The system architecture includes a client interface, load balancer, web servers, product catalog, user management, shopping cart, order processing, payment gateway, inventory management, reviews and ratings, caching and content delivery, analytics and monitoring, search functionality, and more. - Clarifying questions should be asked to gather information about the expected user base, geographical scope, product diversity, third-party seller integration, availability and performance targets, security considerations, payment methods, mobile support, personalization and recommendations, internationalization and localization, and analytics and reporting.
- The database design for the e-commerce system includes tables for users, products, orders, order items, reviews, shopping carts, categories, and vendors/manufacturers.
- Optimization techniques such as indexing, normalization, and data partitioning can be considered.
- The design should focus on scalability, efficiency, data integrity, and security.
- The specific design decisions may vary based on requirements and constraints, and it’s important to discuss and validate design choices during the interview.
