Google Interview System Design Questions

How Do You Answer System Design Interview Questions

Google Systems Design Interview With An Ex-Googler

Ask questions to the interviewer for clarification: Since the questions are purposefully vague, it is advised to ask relevant questions to the interviewer to ensure that both you and the interviewer are on the same page. Asking questions also shows that you care about the customer requirements.
Gather the requirements: List all the features that are required, what are the common problems and system performance parameters that are expected by the system to handle. This step helps the interviewer to see how well you plan, expect problems and come up with solutions to each of them. Every choice matters while designing a system. For every choice, at least one pros and cons of the system needs to be listed.
Come up with a design: Come up with a high-level design and low-level design solutions for each of the requirements decided. Discuss the pros and cons of the design. Also, discuss how they are beneficial to the business.

The primary objective of system design interviews is to evaluate how well a developer can plan, prioritize, evaluate various options to choose the best possible solution for a given problem.

Faqs On Google Tech Interviews

Q. Are coding rounds more important than design rounds at the Google interview?

For junior software positions, coding rounds are more important than design rounds. For senior developer and managerial positions, design rounds and behavioral rounds hold more weight in hiring decisions.

Q. What type of behavioral questions are asked at Googleâs technical interview?

Behavioral questions asked at Googleâs interview are typically around the following topics:

Learn About Google’s Culture

Most candidates fail to do this. But before investing tens of hours preparing for an interview at Google, you should take some time to make sure it’s actually the right company for you.

Google is prestigious and it’s therefore tempting to assume that you should apply, without considering things more carefully. But, it’s important to remember that the prestige of a job won’t make you happy in your day-to-day work. It’s the type of work and the people you work with that will.

If you know any engineers who work at Google , then it’s a good idea to talk to them to understand what the culture is like. In addition, we would recommend reading the following resources:

Design Dropbox/google Drive/google Photos

Design a file or image hosting service that allows users to upload, store, share, delete and download files or images on their servers and provides synchronization across various devices.

Things to discuss and analyze:

Approach to upload/view/search/share/download files or photos from any device.
Service should support automatic synchronization between devices, i.e., after updating a file on one device, it should get synchronized on all devices.
ACID property should be present in the system.
Approach to track permission for file sharing.
Allowing multiple users to edit the same document.
The system should support storing large files up to a GB.

Design Dropbox Or Google Drive

Design a file hosting service like Dropbox or Google Drive. Cloud file storage enables users to store their data on remote servers. Usually, these servers are maintained by cloud storage providers and made available to users over a network . Users pay for their cloud data storage on a monthly basis.

Requirements

Users should be able to upload and download their files/photos from any device.

Users should be able to share files or folders with other users.

Our service should support automatic synchronization between devices, i.e., after updating a file on one device, it should get synchronized on all devices.

The system should support storing large files up to a GB.

ACID-ity is required. Atomicity, Consistency, Isolation, and Durability of all file operations should be guaranteed.

Our system should support offline editing. Users should be able to add/delete/modify files while offline, and as soon as they come online, all their changes should be synced to the remote servers and other online devices.

Extended Requirements

The system should support snapshotting of the data, so that users can go back to any version of the files.

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Design Facebooks Newsfeed System

Facebooks newsfeed allows users to see what is happening in their friend’s circle, liked pages and groups followed.

What are some of the Required Features?
Generate newsfeed using posts from other system entities that the user follows.
Newsfeed posts can be of text, image, audio or video format.
Append new posts to the users newsfeed in close to real-time.

What are some of the Common Problems encountered?

What happens if the new post sees a lot of latency to get appended to the news feed?

Can the algorithm handle sudden user load?

What posts should take priority for displaying in the news feed?

Possible tips for consideration:

Evaluate the process of fanout for publishing posts to the followers

Check how sharding can be achieved efficiently for handling heavy user load. The feed data of a user shouldn’t be put into multiple servers. Instead, sharding can be done on user ids.

How Do You Design A Shared Drive

Hiring managers ask this to explore algorithm basics and backgrounds. Before you begin, make sure you understand the purpose of the task. Knowing if the changes will be registered in real time, if locking will be necessary and if it needs to be naturally convergent will help you give a complete answer.

Example:”This system works on differential synchronization. It is keeping two or more copies of the same document synchronized with each other in real time, so if a change is made on one version, the same alteration happens on all the others. It is a complex challenge, but differential synchronization is scalable and fault tolerant. The three common approaches are ownership, event passing and three way merges. I last had to do this to support in-house document sharing for one of our clients. They wanted real-time collaboration, so three-way merging was not a good option since changes are lost and cannot take effect, as major collisions are common. I used event-passing to allow for real-time collaboration as the locking or ownership approach would only allow the first one opening the document to make any adjustment. This served our client well, as its employees were able to work collaboratively even when out of office or on different schedules.”

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Ready To Ace Your Next Interview

Regardless of whether you want to land a job as a software developer or software Engineer, our expert recruiters can help you prepare for interview questions and improve your chances of getting the job.

Recruitmently connects you with a recruiter who can provide courses, career coaching, and interview preparation advice tailored to your needs so that you may enhance your technical interview skills! So book a recruiter today!

Interview Questions For Software Developers

Prepare for Your Google Interview: Systems Design

How do you design efficient APIs?
What are some caching strategies for web applications?
How can you measure the performance of a scalable system?
What is the best way to handle replication in a distributed system?
How do you partition data when scaling a database?
What sharding techniques are available?
How do you scale distributed applications?
What does a firewall do in network security and its limitations?
Describe the basics of networking.
How can you increase the capacity of an existing system to accommodate more users?

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If You’re Comfortable With Git

Create a new branch so you can check items like this, just put an x in the brackets:

Fork the GitHub repo:https://github.com/jwasham/coding-interview-university by clicking on the Fork button.

Clone to your local repo:

git clone [email protected]:< your_github_username> /coding-interview-university.gitcd coding-interview-universitygit checkout -b progressgit remote add jwasham https://github.com/jwasham/coding-interview-universitygit fetch --all

git add .git commit -m "Marked x"git rebase jwasham/maingit push --set-upstream origin progressgit push --force

Have Questions For The Interviewer

Some of mine :

How large is your team?
What does your dev cycle look like? Do you do waterfall/sprints/agile?
Are rushes to deadlines common? Or is there flexibility?
How are decisions made in your team?
How many meetings do you have per week?
Do you feel your work environment helps you concentrate?
What are you working on?
What do you like about it?
What is the work life like?
How is the work/life balance?

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System Design Interview Questions Concepts You Should Know

You may have heard the terms “Architecture” or “System Design.” These come up a lot during developer job interviews especially at big tech companies.

I wrote this in-depth guide when preparing for my FAANG software engineering interviews. It covers the essential software system design concepts you need to reason your way through distributed systems, and it helped me get into Google as an engineer, after more than 15 years of being a corporate lawyer.

This is not an exhaustive treatment, since System Design is a vast topic. But if you’re a junior or mid-level developer, this should give you a strong foundation.

From there, you can dig deeper with other resources. I’ve listed some of my favourite resources at the very bottom of this article.

I’ve broken this guide into bite-sized chunks by topic and so I recommend you bookmark it. I’ve found spaced learning and repetition to be incredibly valuable tools to learn and retain information. And I’ve designed this guide to be chunked down into pieces that are easy to do spaced repetition with.

Let’s get started!

System Design Scalability Data Handling

You can expect system design questions if you have 4+ years of experience.

Scalability and System Design are very large topics with many topics and resources, sincethere is a lot to consider when designing a software/hardware system that can scale.Expect to spend quite a bit of time on this
Considerations:
Distill large data sets to single values
Transform one data set to another
Handling obscenely large amounts of data

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Most Common System Design Interview Questions

Before we get to a complete list of system design interview questions, lets take a minute to go over the five most common questions that we found in our research.

These questions come from Glassdoor interview reports by software engineers, engineering managers, and technical program managers at Amazon, Facebook, Google, and Microsoft.

Together, these five questions made up nearly 30% of the system design interview questions that we collected across these roles.

To help you prepare answers to these questions, weve included a framework that you can use to structure your thinking. For the sake of brevity, we wont be writing out entire sample answers for each question, but well be linking to full answers that you can use to check your work.

Lets get started.

Systems Design Interview Tips To Keep In Mind

You could falter on the day of the interview, no matter how well-prepared you are. Here are tips on how to make a good first impression during your google systems design interview:

Before you can solve a problem, you should first understand it: It’s essential to understand the issues thoroughly before solving them. Before you start working on a solution, ask the hiring manager your doubts. To acquire an understanding of what is required, ask the appropriate questions. Ask questions about latency, scalability, and scale.

Consider how you’ll put your ideas into action: Once you have a solid understanding of the problem, start outlining your solution. Keep in mind that recruiters are interested in how you’ll execute your ideas, not just what they are.

Your solutions should be realistic and feasible: Don’t propose outrageous or impossible solutions hiring managers will see right through them. Make sure your solutions are achievable and can be implemented without too much trouble.

Be prepared to defend your ideas: You’ll likely be asked to explain and defend your solutions during the interview. Be ready to answer tough questions and justify your choices.

Stay calm and collected: Even if you’re feeling overwhelmed, try not to show it. Remain calm and professional throughout the interview. Collect your thoughts before responding to the interviewer’s questions.

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Question : Design An Autocomplete Feature For Search Queries

Another common interview question is designing a search autocomplete feature. This interview question is essential. Your system design interview answer should be:

Support real-time search by building a quick index
Manage multiple indexes and keep them updated in real-time
Handle user queries without losing efficiency or performance when the number of queries increases with time

Here are some sorts of Google system design software engineering intervie questions as well as software developers that you may expect:

Design A Url Shortening Service Like Tinyurl

Google Maps System Design Interview Question

Design a URL shortening service like TinyURL. This service will provide short aliases redirecting to long URLs.

Functional Requirements:

Given a URL, our service should generate a shorter and unique alias of it. This is called a short link. This link should be short enough to be easily copied and pasted into applications.

When users access a short link, our service should redirect them to the original link.

Users should optionally be able to pick a custom short link for their URL.

Links will expire after a standard default timespan. Users should be able to specify the expiration time.

Non-Functional Requirements:

The system should be highly available. This is required because if our service is down, all the URL redirections will start failing.

URL redirection should happen in real-time with minimal latency.

Shortened links should not be guessable .

Extended Requirements:

Analytics e.g., how many times a redirection happened?

Our service should also be accessible through REST APIs by other services.

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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.

Question : Design A Video Streaming Service

A common design interview question is to create a worldwide video streaming service like Netflix or YouTube.When it comes to creating a video streaming service, your ideal answer should be:

Discuss client design components, backend, and OC
Allow many users to view and share videos at the same time by scaling well
Be able to transmit and store petabytes of information
Count and show the number of downvotes, upvotes, and views on individual videos
Allow users to make comments on videos in real-time
Allow the user to upload, search, and view videos

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How Would You Design Dropbox

Dont jump into the technical details immediately when you are asked this question in your interviews. Do not run in one direction, it will just create confusion between you and the interviewer. Most of the candidates make mistakes here and immediately they start listing out some bunch of tools, frameworks, or databases. Remember that your interviewer wants high-level ideas about how you will solve the problem. It doesnt matter what tools you will use, but how you define the problem, how you design the solution, and how you analyze the issue step by step. In this blog, instead of talking a lot about the web kind of services, we will assume there is a sync client installed in your computer or system and that client is always looking into particular sync folders in which it is always monitoring the changes to the files and uploads it. Also, we wont be talking about how we build cloud storage. We will use some cloud storage services like Amazon S3 or any other storage services that keep the file in the cloud.

Topics To Prepare For Systems Design Interview

The systems design interview rounds aim at testing how you break down a large problem and tackle different parts of it. So while your tech skills are important, your critical thinking is also at display during these rounds. Narrowing down the topics to prepare for such an interview is not easy.

However, based on our experience of training over 9,000 software engineers, the following are some of the key broad categories that you should consider while preparing for a systems design interview:

Basics of systems design
Measuring the performance of scalable systems
MapReduce and distributed file systems
Systems design case studies

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Topics To Expect In A Systems Design Interview

The interview questions for system design aim to see how you break down a large issue and tackle various parts of it. You will be given a problem to solve, and recruiters expect you to take the initiative in the interview and ask clarifying questions.

The interview is not different from a regular conversation therefore, keep your answers short and simple. While your technical skills are essential, your critical thinking will be evaluated in these stages. It’s difficult to narrow down the topics for such an interview.

However, according to the expertise of top-rated recruiters, the following are some of the essential categories to consider while preparing for a systems design interview questions for software engineering and developers:

Basics of API design
MapReduce and distributed file systems
Storage and retrieval
Measuring the performance of scalable systems
Sharding techniques
Basics of systems design

Designing Yelp Or Nearby Friends

Design a Yelp like service, where users can search for nearby places like restaurants, theaters, or shopping malls, etc., and can also add/view reviews of places.

Functional Requirements:

Users should be able to add/delete/update Places.

Given their location , users should be able to find all nearby places within a given radius.

Users should be able to add feedback/review about a place. The feedback can have pictures, text, and a rating.

Non-functional Requirements:

Users should have a real-time search experience with minimum latency.

Our service should support a heavy search load. There will be a lot of search requests compared to adding a new place.

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