Tuesday, July 9, 2024

How To Approach System Design Interview

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What To Expect In A System Design Interview

System Design Interview – Approach and structure – How To [Part1]

Great engineers spend years of time building a robust and scalable system. You cannot possibly come up with a similar solution in a short duration of 11.5 hours in a System Design interview.

So generally only a part of the entire system is discussed in this round.

As mentioned earlier there is no one right solution in designing a good system. This round is generally open-ended and discussion can go in any direction based on what the interviewer is interested in, how you lead the discussion, and in what direction you take it.

Product And Design Sense

Frontend engineering is a highly collaborative role. We work closely with designers, product managers, and backend engineers. Viewing a particular problem through the lens of each of these disciplines is empowering. It allows you to view a problem space through many different lenses. And avoids the if all you have is a hammer, everything looks like a nail issue highly specialized people tend to have.

General knowledge of UX trends and patterns is also useful because they open up different ways of solving a particular problem. It goes a long way if you can proactively identify potentially poor user experiences, bottlenecks, or issues with the UI design.

The frontend applications we are building are expressed in a particular style of common user interface elements. Having knowledge of general UI patterns and their trade-offs from a UX perspective can help you think of different solutions and weigh them up.

As one simple example, if youre asked a scaling question, such as how would we handle 1000X of whatever it is we are rendering. One way of thinking about this is to only show what is relevant to the user and to defer and hide what is not immediately relevant. You can utilize many established patterns whenever we cant fit something into the screen at once.

virtualized list, paginated tables, tabs, scroll view, drawer, master-detail pattern, full page navigation, modal, combo box, collapsible sections etc

Define The Key Features

Once that is out of the way, your next step is defining what kind of features your hypothetical service must possess. Even though your task is designing an already existing service from scratch, it doesnt mean they should be identical.

For instance, if youre tasked with designing Facebook, you can take the features this social media has as the basis and work from that. Think of ways you can combine Messenger and Facebook into one app instead of two or suggest how to make ads more user-friendly.

If youre tasked with developing a Discord-like chat, youll need to include secure chat rooms with stable voice chat features. You can also suggest a streaming option. If you need to develop a digital product marketplace such as Pro Essay Writer, youll need to combine features like dynamic display of offers, secure access to database, and several payment options. You can throw in a live chat or a monitoring feature to make sure the freelancer the user has hired is busy working on the project.

This will show the interviewers that youre not only capable of reverse-engineering a service, but actually thinking about the problems customers face and solving them.

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Crack The System Design Interview: Tips From A Twitter Software Engineer

I recently wrote about how I landed offers from multiple top-tier tech companies. During my interview preparation process, I read up on a lot of material and prepared a set of notes on how to tackle system design problems. In this article, Id like to share those tips with you all.

If youre a fresh graduate with no experience in large-scale distributed systems, or even a seasoned engineer with years of experience under your belt, this article will be useful for you.

Update : If youd like to join a group of students to learn more about system design, Im organizing a small class together! You can go to this link to learn more, or visit my website: zhiachong.com for more info.

This article is broken down into the following four sections:

  • Ask clarification questions
  • Keep your own notes

How To Answer System Design Interview Questions

System Design Interview: Instagram or a Similar App (Snapchat, Flickr ...

First and foremost, the system design interview is designed to evaluate your capability to produce technical solutions to abstract problems. As you can probably already tell, system design interview questions are meant to simulate the real-world problems candidates would tackle in their roles.

As such, they’re not designed with a specific correct answer, nor will hiring managers be looking for one. Interviewers use these types of system design interview questions to evaluate how you think and approach solving complex technical problems.

You must explain the various options or paths a potential solution can take, along with the tradeoffs and drawbacks of each.

Believe it or not, system design interview rounds are usually incredibly influential on which level you are hired if you receive an offer.

Despite how influential these interview questions are, don’t be nervous! Use this framework to ensure you answer the question as effectively as possible, both in practice and real life.

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What Is A System Design Interview

A system design interview is conducted to allow candidateslike programmers, designers, developers and software engineerssufficient opportunity to prove expertise in the field through the tangible application of knowledge to solve a real problem that a company might be facing.

The system design interview is typically conducted later in the interview process. It is a trial intended to see how well you work on a team and your approach to problem solving using open-ended questions to arrive at the best possible solutions. A system design interview analyzes your process in solving problems and creating designing systems to help clients. It is an opportunity for you to show the hiring manager and potential team that you are a valuable asset and display your skills and expertise in a concrete way.

Related:Learn About Being a Computer Engineer

Front End System Design Interview Overview

There are shockingly few front end system design resources out there, probably because there’s a lower demand and supply for front end engineer candidates.

“System” here typically refers to front end systems, which are quite different from the typical distributed system design questions for Software Engineering interviews. The questions asked can be quite similar to the possible questions in “Build user interfaces” format but with more focus on architecture and design. There’s a significant amount of overlap between them – you will likely need to do some design when you build UI, and also do some coding here to illustrate your ideas/app state format.

The difference between this section and the “Build user interfaces” format is that the questions here are usually larger. If the session is only half an hour, candidates are expected to talk about the design tradeoffs, possible implementations, instead of coding it out. Because system design questions usually involve multiple components and knowledge across the web stack, candidates usually do not have to go very deep into the lower-level details of each component and can keep the discussion at a higher level, about API design between the client and server, and API between the components.

The two main kinds of front end system design interviews are UI components and applications.

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Basic Concepts Of System Design

Here, we take you through some important system design topics you should prepare on:


Scalability defines the range of capabilities in which a system can be used. Vertical Scaling refers to powering up the system by adding more machines to an existing system. In contrast, Horizontal scaling, also referred to as scaling out, means adding resources so that the defined ceiling limit remains untouched.

Load Balancing and Caching:

A load balancer can be hardware or software. Its main purpose is to increase the reliability and performance of the system by distributing the load over multiple computing nodes.

Caching is the process of storing copies of application data that is frequently used. As a result, caching improves throughput, computing costs, and data retrieval time.

Data Replication:

Data replication is storing data in more than one location. This allows the system to reduce network latency, decrease fault-toleration issues, and increase availability.

Network Protocols And Proxies:

Properly defined protocols in a network infrastructure simplify data flow and improve throughput. In addition, network protocols are the key to how a system’s components interact.


A database is where a system’s data can be stored, updated, deleted, and returned for query. It is essential to mention the CAP Theorem here:

Performance Measures:

Additional system design topics to prepare:

How To Approach System Design Interview

How to approach System Design Interview?

Related tags:

System design questions is likely to be asked in the final technical round of a tech interview of top companies like Amazon, Microsoft, Google, Uber, and other large-scale tech start-ups. Such a type of interview is an open-ended conversation, where as a candidate, we are expected to lead it along with a discussion with the interviewer.

In this blog, we will discuss some steps to solve system design problems during an interview.

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    The Architecture Of Large

    You would have to learn about topics like:

    N-Tier applications

    Processing happens at various levels in a distributed system. Some processes are on the client, some on the server, and others on another server – all within one application. These processing layers are called tiers, and understanding how those tiers interact with each other and the specific processes they are responsible for is part of system design for the web.

    HTTP and REST

    HTTP is the sole API on which the entire Internet runs it is the system through which we send every email, stream every Netflix movie, and browse every Amazon listing. REST is a set of design principles to directly interact with the API that is HTTP, allowing efficient, scalable systems with components isolated from each others assumptions. Using these principles and open API makes it easier for others to build on your work or extend your capabilities with extensions to their own apps and services.

    DNS and Load Balancing

    If you have 99 simultaneous users, load-balancing through DNS routing can ensure that servers A, B, and C each handle 33 clients, rather than server A being overloaded with 99 and servers B and C sitting idle. Routing client requests to the right server, the right tier where processing happens, helps ensure system stability. You need to know how to do this.


    Stream Processing

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    What Is The Difference Between High

    High-level design focuses on what the problem is you’re trying to solve. Low-level design breaks down how you’ll actually achieve it. That includes breaking down systems into their individual components and explaining the logic behind each step. System design interviews focus on both high-level and low-level design elements so that your interviewer can understand your entire thought process.

    Top 10 System Design Interview Questions And Answers

    Approach for System Design Interviews + Uber/Lyft Design

    In the software engineering interview process system design round has become a standard part of the interview. If you want to get your dream job in some big tech giant companies then you need to tell your approach to build a complex large scalable system. There is no standard or accurate answer to the design interview questions.

    You may have different conversations with different interviewers. Due to the lack of experience in building a large-scale system and the open-ended nature of the system design round a lot of candidates struggle with this round. Not just junior and mid-level developers but also experienced developers feel uncomfortable in the system design round. If you are preparing yourself for this round then we recommend you to read the blog How to Crack System Design Round in Interviews. Along with this, if you also want to crack Architect, SDM, SDE, and SSE jobs then you can check out the System Design Live course and optimize your approach towards getting an amazing job.

    We will discuss some common design interview questions asked by the interviewers frequently in big tech companies. We will also discuss some key points, that you should consider while designing the system and explaining the answer to the interviewer.

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    Practice With Mock Interviews

    The first step is always to practice by yourself, as we touched on above. Once youve got the framework down, start interviewing yourself out loud as you practice. Play both the role of the interviewer and the candidate, asking and answering questions. This will help you develop your communication skills and your process for breaking down problems.

    Books Grokking System Design Interview And Grokking Object

    Grokking system design interview a very good book. Provides you with core 10 use cases one of which you are usually asked at system design sessions. But examples in the book do not deeply dive into details of software realization and provide only general overview of components design .

    Grokking object-orienteddesign interview book provides interesting detailed reviews of architecturing classes diagrams, process diagrams and realization of key classes in code.Code available on both: Java and Python.

    3. The examples from the books above as well as examples from the coding interviews with solutions you can find in this nice resource

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    System Design Interview Questions

    The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed’s data and insights to deliver useful tips to help guide your career journey.

    Interviewing for a position requiring system design expertise is an opportunity to discuss your experience and highlight your ability to create complex systems. When speaking with a potential employer, how you communicate your knowledge can help you prove that you are a qualified candidate for the job. You can prepare for your job interview by studying basic design principles and planning answers to possible questions about these ideas. In this article, we review common system design interview questions and answers to help you prepare for your next interview.

    Example Question : Design Reddit

    Amazon System Design Preparation (SIP)

    “Let’s pretend that you are the lead engineer tasked with building a platform like Reddit from scratch.

    Assume youre given the following requirements:

    • Users can make posts in different forums ,
    • Users can include images in their posts,
    • Users can upvote or downvote posts they like or dislike,
    • Users can leave comments on posts,
    • The system has a news feed of posts sorted by both ranking and recency of posts.

    The question would come with the following constraint:

    • The system must be able to support large volumes of users viewing and posting content simultaneously.

    Design Reddit Interview Question: Our Answer

    There’s no denying this is a broad system design question. We will follow a similar approach as we did for the previous question.

    First, we will define the problem space. This, again, means clarifying the requirements. In this sample system design interview question, the interviewer gave you a concrete list of necessary features.

    Still, you should first dig deeper into the requirements for additional clarification and detail. For instance, you can ask questions like:

    • Does our system need to support users on mobile and the web, or just one or the other?
    • Will the images be uploaded to the system itself, or will they be links to another hosting service?
    • Are there any necessary performance-related features that would influence our system design and require load balancing?

    Let’s imagine your interviewer stated you only need to be concerned with web users.

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    Design A Parking Lot System

    • What are some of the Required Features?
    • The parking lot can have multiple levels where each level has multiple rows for parking spots.
    • The parking lot can support parking for cars, buses, motorcycles hence spots can be of multiple sizes.
    • Consider the parking lot capacity at the time of designing the system.
    • Design appropriate pricing for each parking spot.
  • What are some of the Common Problems encountered?
  • What should happen to the parking lot system if every spot is occupied?
  • Assigning parking lot spots of smaller size to vehicles of a bigger size.
  • Possible tips for consideration:
  • Think of an algorithm for assigning an appropriate parking spot to a vehicle.
  • Think of different entities required for designing the system.
  • Creating Design Artifacts And Building Momentum

    The primary tool used in frontend system design interviews is the whiteboard. Utilizing it effectively means youll want to show a clear thought process by taking whats in your head and laying it out in structured sections.

    If the input to a frontend system design interview is a vague question. The output is a clearly defined set of requirements, prioritized use cases, a high-level plan, and a design on the whiteboard. Additionally, its a shared understanding between you and the interviewer of the overall solution and its pros and cons.

    This ability is an important skill to have when working on a team when designing features. Providing this structure for the team allows others to chime in with ideas versus just having them in your head. Providing this space for input is essential if youre a technical lead on a team.

    At the end of the interview, ideally, you could hand over the whiteboard to someone else, and they would have a high-level understanding of what is required, and a good idea for the solution explored. Creating design artifacts on the whiteboard as you move through each interview section will help you build momentum and confidence throughout the interview.

    Next, well dig into the distinct stages in the frontend system design interview. Along with what tangible design artifacts we should be focussed on creating in each stage.

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