How to Crack a System Design Interview

System design interviews form an integral part of the interview process for senior positions at reputed FAANG companies. As these tech giants are focused on designing applications for their wide consumer base, they are particularly demanding while selecting their software engineers, software developers, and coding engineers. If you wish to be a part of the Big Five, we are here to help you get started. 

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The article is going to cover the following:

1. System Design Interview
2. How to Prepare for a System Design Interview?
3. System Design Interview Sample Questions and Answers
4. Approach to Solve System Design Interview Problems
5. Practice Problems for System Design Interview Preparation
6. How to Ace System Design Interview at FAANG?
7. FAQs

System Design Interview

• System design interviews are a crucial part of all technical interviews conducted for senior roles. The purpose of conducting a system design interview is to get a brief idea of your knowledge and experience in the field. 
• The round's duration is on average 45-60 mins, and you’ll be given a broad topic to work on. You can ask any number of clarifying questions to fully understand the question and avoid making any assumptions. 
• This round of interviews is a little different from the usual coding or behavioral rounds, so a keen understanding of the subject and dedicated preparation are necessary to crack this round. 

System Design Interview Preparation

System design interviews have a lot of weightage in the entire interview process, so it is important to prepare for them before appearing for any FAANG company interviews. System design interview preparation can be divided into the following key points: 

1. System Design Interview Preparation Books

Books are an ocean of resources. These books provide dense knowledge and are generally less preferred. However, if you find reading and highlighting important points more effective than watching course videos, then here are some books that might come in handy while preparing for system design interviews:

1. Understanding Distributed Systems- Robert Vitillo (Principal Engineer at Microsoft)
2. System Design Interview: An Insider’s Guide- Alex Xu
3. Design Data: Intensive Application

2. Refer to System Design Articles and Videos

There are plenty of interview articles and videos on the internet for aspiring software engineers, coding engineers, and tech leads to refer to while preparing for the technical interview. Articles and videos provide concise information unlike the books and hence is sometimes more preferred. 

3. Interview Prep Courses

Acing FAANG interviews is difficult, and the process becomes unbearable if one enters the interview arena with no prior knowledge about the process. There are plenty of interview prep courses available to choose from. Interview Kickstart has courses specifically targeting job profiles at FAANG companies. To know more, Sign up for our FREE Webinar.

4. Mock Interviews

Mock interviews are proven to be one of the most successful strategies to crack any interview. Mock interviews conducted by hiring managers of the concerned company can give the applicant a brief insight into the process, types of questions asked, and more. 

System Design Interview Sample Questions and Answers

For software engineers, software developers, and tech geniuses who are confused about how to prepare for a system design interview, here is one of the many suggestions any expert in the field would give: to practice sample questions. Here are a set of few sample system design interview questions and their sample answers:

1. What metrics should be used for monitoring a system’s performance?

Sample Answer: The three commonly used metrics to assess a system’s performance are Latency, Availability, and Throughput. An important feature of these metrics is that they allow the system designer to understand the user’s experience while using a particular system. Each of the metrics focuses on individual properties like latency is related to the speed at which a particular message is delivered, availability is referred to how often a system responds to the user’s input, and lastly, throughput helps in understanding the amount of data traveled to the user. 

2. How would you add micro-services to an already existing E-commerce platform?

Sample Answer: Micro-services can be added by interconnecting platform APIs throughout a distributed system. 

3. What is load balancing, and state its importance in system design?

Sample Answer: Load balancing helps improve the quality of a system design and hence is an essential process. The purpose is to allocate tasks across computing nodes to ensure the system’s proper functionality. The two important load balancers are L4 and L7.  

Approach to Solve System Design Interview Problems

While practicing, it is important to follow a framework or a pattern of solving. This will help you solve even unseen questions at the time of the interview. You can use the following approach: 

Step I: Define End Goals

• It is better to clarify all the doubts before formulating a solution.
• An individual should have answers to questions like ‘What is the end goal of the system? Who is the target audience? What are the expected inputs and outputs of the system?’
• After confirming that you and the interviewer are on the same page, proceed with Step II with the right set of answers. 

Step II: Establish and Understand the Scope

• Prioritize and list out a set of features according to your understanding of the system and discuss it with the interviewer.
• Ask relevant questions like whether the system has end-to-end experience or API, ask about the platform on which the system will interact with the clients. 

Step III: Design the System as per the Required Scale

• It is important to define the system's scalability before developing it to confirm whether the data you are working on will fit on the machine or some alteration will be needed. 
• Scale is important as a lot depends on it, like the response time, the data limitation, and expected read to write ratio. 

Step IV: Start Big, Then Drill Deeper.

• Having the outline ready at first with broad features in place can help in the efficient development of the system. 
• Once your end-to-end details have been fixed, like backend services, offline processes, and network framework, work on the system’s entry points and other fine details. 

Step V: Algorithm, Data Structure, and Coding

• Data structure and algorithms are important to develop a system. As each system design has its own set of algorithms and data structures, it is good to have sound knowledge of data structure concepts and algorithms. 
• Apart from approaching the problem by following the steps mentioned above, it is important to give a real-time update about the complexity of the process and your method of circumventing it so that the discussion is on and the interviewer is keen to see your result. 

Practice Problems for System Design Interview

System Design interview questions are broad, open-ended, and have multiple correct answers. Some examples of questions asked during the system design Interview are: 

1. Design a tiny URL system
2. Design Facebook messenger
3. Design a ride-sharing system
4. Design an autocomplete system, where suggestions will pop up while typing a search query. 
5. Design a payment gateway system

For more system design interview questions, read:
Google System Design Interview Questions
Amazon System Design Interview Questions
Facebook System Design Interview Questions

How to Ace System Design Interview at FAANG?

How to prepare for a system design interview? How to clear coding interviews? What is the interview prep guide for system design? How to ace the coding interview system design? These are some questions that cloud an individual’s judgment while appearing for the position of software developer, software engineer, coding engineer, or tech lead. We at Interview Kickstart are here to help you prepare for your next technical interview.

To get placed as a system engineer at one of the reputed FAANG companies, one needs a reliable guide and a well-planned schedule. Interview Kickstart is here to smoothen this tough path of achieving your dream job. We have wide knowledge and understanding of the nitty-gritty of finding a job.

Since its inception in 2014, Interview Kickstart has helped thousands of engineers achieve their dreams. With our exclusive courses, we empower engineers to get better acquainted with the intricacies of their chosen field and provide them with the right guidance to clear tech interviews at reputed companies. At Interview Kickstart, we have courses that holistically prepare you for an interview. 

Want to learn more? Sign up for our FREE webinar on How to Nail Your Next Tech Interview.

FAQs

1. System design interviews are a part of which company’s interview process?

System design interview is a crucial round for all senior-level positions. Here are some of the companies and the roles for which system design interview is a must:

1. Facebook Software Engineer
2. Google Software Engineer
3. Facebook Technical Engineer Manager
4. Amazon Software Development Engineer

2. What is the average salary earned by a software engineer in the United States?

$101,575 is an average software engineer’s salary. This amount is not just restricted to reputed tech giants but all tech companies in the US. Read Google Software Engineer Salary and Facebook Software Engineer Salary to learn more about software engineer salaries at FAANG.

3. What are the fundamental system design concepts that one should not miss?

Before the interview, brush up on fundamental concepts like databases, load balancing, latency, throughput, availability, sharding, and caching. For a comprehensive list of topics, check out the Technical Interview Checklist.