Top 10 Topics for System Design Interviews - Part 1

Hello friends, if you have attended technical interviews then may know that the System Design part is one of the toughest to crack. I’ve asked myself why this happens and I found that most developers are not familiar with essential System design topics or concepts. Earlier I shared software architecture books which are also great for system design interviews. Today I’ll discuss key topics you must know to be prepared for system design interviews.

As I have said before, System design interviews are a crucial part of the hiring process for software engineers and developers and you must prepare for it, leaving it to chance is not a good idea. These interviews assess your ability to design scalable and efficient systems to solve real-world problems.

To excel in system design interviews, it's essential to have a strong grasp of the fundamental concepts and principles.

This is the first part of the series and in this part, we will see the top 5 system interview topics.

By the way, if you are preparing for System design interviews and want to learn System Design in-depth then you can also refer to sites like ByteByteGo, and DesignGuru, which have many great System design courses and tutorials.

Here is a nice system design cheat sheet from DesignGuru for quick revision:

5 Essential System Design Topics for Interviews

To stand out from the competition in system design interviews, it's crucial to have a solid understanding of key concepts that set you apart from other candidates.

By mastering these ten system design concepts, you can position yourself ahead of 99% of candidates and impress interviewers with your expertise.

1. Scalability

Scalability is crucial in system design as it ensures a system can handle increasing loads and maintain performance. To design scalable architectures, you should understand concepts like horizontal and vertical scaling, load balancing, and distributed systems. Those will help you with tech interviews.

2. Availability and Fault Tolerance

Designing fault-tolerant systems is essential to maintain availability even in the face of failures.

As a candidate, you should learn about replication, redundancy, failover mechanisms, and fault tolerance techniques like backups, checkpoints, and error handling.

For high availability many companies create active-active or active-passive architecture as shown below, The best example is cloud computing companies like AWS and Azure which have data centers in different parts of the world, and if one goes down then server clients from others.

3. Data Storage and Databases

Different applications require different types of data storage. You should familiarize yourself with different types of databases like relational databases, NoSQL databases, key-value stores, and columnar databases.

You should understand their strengths, weaknesses, and use cases.

One of the common questions and concepts to understand here is SQL vs NoSQL as they often come during different questions, here is a nice diagram that highlights the difference between SQL and NoSQL

4. Caching

Caching helps improve performance by storing frequently accessed data closer to the users. In this topic, you should learn about caching techniques, caching strategies, cache eviction policies, and cache coherence to design efficient caching systems.

You should also get yourself familiar with things like cache hit and cache miss and here is a nice diagram for quick reference:

5. Message Queues and Event-driven Architecture

Message queues enable asynchronous communication between different components of a system. While preparing for this topic you should understand concepts like pub-sub (publish-subscribe) patterns, message brokers, event-driven architecture, and their applications in building scalable and loosely coupled systems.

In the past, I wrote about Apache Kafka vs ActiveMQ vs RabbitMQ which is a good starting point for learning about message brokers and queues.

Here is a nice diagram showing Event Driven Architecture using the pub-sub model and point-to-point model :

Conclusion

That's all about 5 System design topics you must prepare for tech interviews. Mastering these ten essential system design concepts will significantly enhance your performance in system design interviews.

By understanding scalability, fault tolerance, data storage, caching, message queues, microservices, security, performance optimization, design patterns, and trade-offs, you'll be well-prepared to tackle complex design problems and impress interviewers with your comprehensive knowledge.

Remember, practice and hands-on experience in designing real-world systems are equally important, so apply these concepts in practical scenarios to solidify your understanding. Good luck with your interviews and your future endeavors as a skilled system designer!

By the way, if you are preparing for System design interviews and want to learn System Design in-depth then you can also check out sites like ByteByteGo, DesignGuru, and Exponent, which have many great System design courses.

In the next part, we will take a look at 5 more topics that are important for system design interviews. Stay tuned!