System Design Basics to Advance Concepts Explained for Interview Preparation
Varun Saharawat30 Oct, 2025
System Design Basics is your go-to source for preparation for an interview with a System designer. System design gives a high-level understanding of the elements and their relationships. System Design by Physics Wallah is the ideal course for learning system design basics.
System Design Basics: Are you feeling overwhelmed when thinking about the system design round in your upcoming technical interview? You are not alone! Many software engineers feel anxious and unprepared for this stage of the interviewing process, but don’t lose hope.
With these basic concepts in mind, you can confidently demonstrate your problem-solving skills and show that you have thought through how to design complex systems. Here, we provide insight into some essential basics of system design patterns with an emphasis on preparation for interviews. We wish you luck as you prepare – let's get started!
Whether you are a seasoned engineer or just starting out on your journey, system design is an essential part of preparing for technical interviews. Breaking down problems into their components and building a strategy to tackle them can seem daunting, but with the right resources and practice, it doesn’t have to be! System Design by Physics Wallah is the best course out there for taking the uncertainty out of system design and making sure you can ace any interview.
Also read: A Detailed Guide on Cracking System Design Interviews in 2026!
What is System Design?
[caption id="attachment_5578" align="aligncenter" width="880"]
System Design[/caption]
System design is the process of outlining the architecture, interfaces, and data structure for a system that fulfills specific requirements. It aims to align with the business or organizational needs by creating coherent and efficient systems. Once the requirements are identified, the next step involves crafting a physical system design that caters to customer needs. Choosing between custom development, commercial solutions, or a blend of both influences the system design approach. Executing effective system design mandates a systematic perspective, encompassing considerations from hardware and software to data storage infrastructure.
System Design Basics Concepts
Here are system design basics concepts that you should know before going for an interview:1) Scaling
Scaling, horizontal or vertical, is integral to an application's ability to manage increased workloads without compromising latency. Horizontal scaling, or scaling out, involves adding more hardware to the existing resource pool, enhancing the system's overall computational power. On the other hand, vertical scaling, or scaling up, entails boosting the power of individual servers and augmenting the hardware's capabilities.2) Microservices
Microservices, constituting a modern architectural style, break down applications into loosely coupled services. This modular approach allows for independent service development, deployment, and maintenance. The use of APIs facilitates communication between these services, contributing to the flexibility and scalability of the application.3) Throughput
Throughput, a crucial performance metric, gauges the amount of data or requests processed within a specified time frame. It is particularly significant when handling substantial data volumes or concurrent requests. High throughput is achieved by distributing requests across multiple machines.4) Latency
Latency, another key metric, measures the time it takes for a request to generate a response. It encompasses network travel time, request processing, database queries, and other operations. Low latency results in quick response times, enhanced system performance, and a seamless user experience.5) Network protocols
Network protocols like HTTP and TCP/IP are pivotal in facilitating communication between users and servers. These protocols establish the rules governing interactions over the network.6) Load balancing
Load balancing is crucial for distributing traffic evenly among various servers, preventing overloading on a single server, and avoiding a single point of failure. Load balancers contribute to system reliability by managing traffic and maintaining throughput and availability.7) Databases
Databases essential for storing and retrieving data are classified as relational (e.g., MySQL, PostgreSQL) or non-relational (e.g., Cassandra, Redis). Relational databases enforce strict data relationships, while non-relational databases offer structured and unstructured data flexibility. Database partitioning, dividing a database into smaller chunks, enhances system performance, addressing latency and throughput concerns.8) Distributed messaging systems
Even when geographically dispersed, distributed messaging systems offer a reliable and scalable mechanism for exchanging messages among applications, services, or components. These systems enable independent development and functioning by decoupling sender and receiver components. They are precious in large-scale or intricate systems, such as microservices architectures or distributed computing environments. Notable examples of distributed messaging systems include Apache Kafka and RabbitMQ.Also read: How to Crack System Design Interviews in Top Companies 2024?
System Design Basics Interview Questions
The table below shows the System design basics interview questions:| System Design Basics Interview Questions | |
| Question | Answer |
| What is System Design, and why is it important? | System design is the process of defining the architecture, components, and interfaces of a system to fulfill specified requirements. It is crucial for building efficient and scalable systems. |
| Name the key components of System Design. | The key components include Architecture, Modules, Interfaces, Data, and Procedures. |
| Explain the difference between Horizontal and Vertical Scaling. | Horizontal scaling adds more hardware to the existing resource pool, while vertical scaling adds more power to individual servers. |
| What is Caching in the context of System Design? | Caching is a high-speed storage layer that stores frequently accessed data, reducing the need to fetch data from the original source repeatedly and improving system performance. |
| How do Distributed Messaging Systems work? | Distributed messaging systems facilitate communication by decoupling sender and receiver components, allowing independent development. Examples include Apache Kafka and RabbitMQ. |
| Define NoSQL Database. | NoSQL databases, or "Not Only SQL," handle unstructured or semi-structured data, providing flexibility and scalability. Examples include MongoDB and Cassandra. |
| Why is Load Balancing important in System Design? | Load balancing ensures even distribution of network traffic across multiple servers, preventing bottlenecks and improving system reliability. |
| What is Throughput, and why is it crucial for system performance? | Throughput measures the amount of data or requests processed within a given time, essential for handling large volumes of data or concurrent requests. |
| Why are Network Protocols important in System Design? | Network protocols are rules governing communication between servers, forming the foundation for effective communication in a system. Common examples include HTTP and TCP/IP. |
Also read: Top 10 System Design Interview Questions and Answers
FAQs
What is the difference between Horizontal and Vertical Scaling?
Horizontal scaling, or scaling out, involves adding more hardware to the existing resource pool, increasing the overall computational power. Vertical scaling, or scaling up, entails adding more power to individual servers, enhancing the hardware's capacity to run the application.
What is Caching in System Design?
Caching is a high-speed storage layer that stores frequently accessed data between the application and the source. It helps improve performance by reducing the need to fetch data from the source repeatedly.
How do Distributed Messaging Systems work?
Distributed messaging systems provide a reliable and scalable means of exchanging messages between applications or services. They decouple sender and receiver components, allowing them to function independently. Examples include Apache Kafka and RabbitMQ.
Why is Load Balancing important in System Design?
Load balancing ensures even distribution of incoming network traffic across multiple servers. It prevents a single server from becoming a bottleneck, enhances system reliability, and contributes to maintaining throughput and availability.
Why is Network Protocols important in System Design?
Network protocols are rules governing communication between servers or machines over a network. Common protocols include HTTP and TCP/IP. They form the foundation for effective communication in a system.