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.
This in-depth guide will help prepare you for the System Design interview, by teaching you basic software architecture concepts.
This is not an exhaustive treatment, since System Design is a vast topic. But if youre a junior or mid-level developer, this should give you a strong foundation.
From there, you can dig deeper with other resources. Ive listed some of my favourite resources at the very bottom of this article.
Ive broken this guide into bite-sized chunks by topic and so I recommend you bookmark it. Ive found spaced learning and repetition to be incredibly valuable tools to learn and retain information. And Ive designed this guide to be chunked down into pieces that are easy to do spaced repetition with.
Lets get started!
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Other Than Block Storage Explain Two Other Storage Techniques Designers Consider In System Design
File storage refers to a hierarchical storage mechanism. With this methodology, information is saved in files that are stored in folders, which are then housed in directories. Only a small quantity of data, especially structured data, may be stored using this approach.
This is a type of storage technique for handling large amounts of unstructured data. Due to its dynamic scalability, object storage is the ideal form of data storage for data backups and archiving. An operating system cannot directly access object storage.
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Amazon Software Engineer Interview Guide
Breaking into FAANG companies for tech roles is all about preparation and practice. From getting a resume review for landing an interview call to preparing for the interview to land the offer, it can be a lengthy but rewarding process if you accept the offer. Joining Amazon as a Software Engineer is a dream for many tech candidates, and this FAANG interview guide is to help you realize that dream! In this guide to cracking Amazon Software Engineer interviews, we’ve covered the following:
- Amazon Interview Process and Timeline
- HR Interview + Example Questions
- Technical Phone Screen + Example Questions
- Onsite Interviews + Example Questions
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Briefly Explain What Microservices Mean
These constitute an architectural style, which uses loosely coupled services to structure an application.
It separates a big application into a bunch of independent, modular services. These modules can be created, used, and maintained separately. Traditional monolithic apps cant keep up with the pace and reliability of microservices. Each independent service in the program has its own codebase and logic since the application is divided into separate services. Application Programming Interfaces allow these services to communicate with one another. If a system designer wants to create a more scalable application, microservices are perfect for that. Because of its cutting-edge features and modules, microservices make it considerably simpler to scale applications.
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Analyzing Over 1300 Personal Experiences Of Those Whove Gone Through The Process
In a previous article, I analyzed over 300 personal interviews from those who completed the . Now Im back with part 2 to discuss one of the most sought-after positions in all of tech: software engineer at Amazon. This time, I was able to look over 1,300 experiences.
Youre probably wondering how was I able to find 1,300 people who did the Amazon software engineer interview in person.
Well, it was all thanks to Glassdoor.
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What Are The Major Components Used In Designing A Web Crawler
The primary function of a web crawler is to enhance Google search results by crawling and indexing page links. Storage systems and APIs are mandatory components of designing a web crawler. Also, we have to assess various things: how to find new web pages and how to prioritise web pages. Check this video link to get details.
Are System Design Interviews Difficult
System design interview questions are notoriously difficult to prepare for. Unlike algorithmic questions, they dont reduce down to a handful of prescribed patterns. Instead, they require years of technical knowledge and experience to answer well.
For junior engineers, this can be tricky. Even senior developers sometimes find themselves scratching their head trying to understand a system.
The key to doing well in these types of interviews is to use your entire knowledge-base to think about scalability and reliability in your answer.
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Merge Two Sorted Linked Lists
Given two sorted linked lists, merge them so that the resulting linked list is also sorted. Consider two sorted linked lists and the merged list below them as an example.
def merge_sorted: #TODO: Write - Your - Code return head1
Click here to view the solution in C++, Java, JavaScript, and Ruby.
Runtime Complexity: Linear, O where m and n are lengths of both linked lists
Memory Complexity: Constant, O O
Maintain a head and a tail pointer on the merged linked list. Then choose the head of the merged linked list by comparing the first node of both linked lists. For all subsequent nodes in both lists, you choose the smaller current node and link it to the tail of the merged list, and moving the current pointer of that list one step forward.
Continue this while there are some remaining elements in both the lists. If there are still some elements in only one of the lists, you link this remaining list to the tail of the merged list. Initially, the merged linked list is NULL.
Compare the value of the first two nodes and make the node with the smaller value the head node of the merged linked list. In this example, it is 4 from head1. Since its the first and only node in the merged list, it will also be the tail.Then move head1 one step forward.
The Final Tip For All Candidates Aspiring To Work At Amazon:
As recruiters and fellow SDEs, we want you to succeed and join the company. So, if you feel like you are underprepared for the interviews and need more time, you can always reach out to HR to reschedule your interview to some other date. It is much preferred if you give your interviews being fully prepared than just going through the process and losing your shot at working here- Nishit Patira
Hope this helps, good luck!
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Design An Events Website
Q. Imagine you are a founder of a website that wants to sell tickets for events online. Discuss a plan for releasing a minimum viable product website for this startup and define an architecture to support the requirements.
The following is a representation of a real-life Full Stack System Design interview setting involving a technical architect/staff engineer. Weâve listed examples of follow-up questions to the question listed above and ideal answers for each.
This interview is purely fictitious, and any resemblance to a real-life setting is coincidental.
How Are Performance And Scalability Related To Each Other
The ability to handle a large amount of traffic in any application is referred to as scalability, whereas performance is about testing the speed with which the application is running. The increased performance is directly proportional to the number of resources added to the system. The ability to handle larger data sets in the event of growing work makes scalability directly related to the performance of any design. Performance problems might affect just one user, whereas the system might eventually become slow in case of scalability issues due to heavy data load.
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Design Facebooks Newsfeed System
Facebooks newsfeed allows users to see what is happening in their friends 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.
Example Coding Interview Answer
To illustrate the framework discussed above, weve laid out an example answer to a real coding question that was asked in a , according to data from Glassdoor.
Try this question:
Candidate: Great, let me add some test code.
Interviewer: Looks good. What’s the output?
Candidate: Here it is:
Interviewer: Fantastic! Earlier, we made the assumption that the character set was limited. What would the implications be if that were not the case? Let’s say all Unicode characters are allowed.
Optimize your code
Candidate: All of Unicode is very large, in the region of 150 000 characters I think. That would make the scoreboard array pretty big. It would negatively affect the space complexity of our solution, because it requires a lot of constant space. It would also increase the runtime, as the whole scoreboard array would need to be checked, even though it’s unlikely any strings would be anywhere close to the size of the scoreboard array.
Interviewer: Yeah, it would bog this down substantially. Is there an optimization for this solution that could mitigate those issues?
Candidate: We’d need a way to cut down the size of the scoreboard array, since it will be so sparsely populated with scores. Perhaps if we tried replacing it with a hashmap?
Interviewer: Sounds interesting. Can you explain more?
Interviewer: Great. Will that change the time complexity?
Interviewer: Great. Can you code the changes in?
Candidate: Now I can call that from inside the for loop.
Q& A
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How To Prepare For Amazon Sde Interviews
Nishit explains that most candidates struggle either with their confidence or with their interview preparation routine. He says that the best way to prepare for an interview is to go back to getting your fundamentals right.
You should constantly be trying to apply your skills through various assessments and projects on your own. In HLD, the key concepts like sharding, applications, hashing, etc. become quite important for clearing your interviews. Therefore, having your fundamentals clear can help you not only land the job but also on the job where you constantly need to learn new skills and come up with new ideas.
Nishit recommends GeekforGeeks as an excellent resource to get your concepts sorted. He also mentions that consistently working on problem-solving questions along with a few other role-specific questions can help. Try to satisfy each prerequisite for the SDE role by taking ample time to develop the said skills.
Top 25 Amazon Sde Technical Interview Questions
Are you Preparing for your Amazon SDE Interview? Are you looking to brush up your Algorithms and Data Structures? Being a Software Developer, I know how hard it is to blindly grind Coding Challenges, taking the time to understand them only to find out, that toil has been wasted away when they dont show up in the interview or worse if you were practicing questions that resemble the same underlying concept
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What Interviews To Expect
First, it’s important that you understand the different stages of your software engineer interview process with Amazon. Note that the process at AWS follows similar steps. Heres what you can expect:
- HR recruiter email or call
- Online assessment
- Phone screens: one to two interviews
- Onsite: four to six interviews
In most cases, the interview process starts with an HR recruiter call to discuss your interests and to see what group or team would be best for you. Your recruiter will also use this conversation to confirm that you’ve got a chance of getting the job at all. You should be prepared to explain your background and why youre a good fit for Amazon. If things go well the recruiter will then send you an online assessment or schedule your technical screen depending on the role you’re applying for.
1.1.1 Amazon online assessments
Amazon primarily uses online assessments for internship and new graduate positions, but also sometimes for experienced positions. You might have to solve up to three different online assessments before progressing to the technical phone screen stage.
OA1: Debugging
Important note: as far as we know, this online assessment is only used for internship and new graduate positions.
OA2: Coding questions
The second online assessment , is a set of two data structure and algorithm questions. Each question needs to be solved within a certain amount of time . And your code must compile for the two questions in order to move forward in the interview process.
The Article Consists Of 3 Parts A Preparation Guide A System Design Template And Design Questions With Links
For my system design interview with Amazon, I watched video lectures, read blog posts, and discussed with my friends various approaches to designing a system. After my extensive preparation, I came up with a template that I followed during my interview and wanted to share and hope it would help anyone preparing for a system design interview.
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Data Structures / Algorithms Question
Candidates typically report that the data structures and algorithms questions are easier than the onsites of other top companies. The difficulty of the coding screen questions ranges from Easy to Medium on the Leetcode scale. This stands to reason. Since each coding screen asks two LP questions, there is not enough time for the coding question to be exceedingly difficult.
See the Resources section below for resources that will help you on the coding screens.
Any Questions About Amazon Software Development Engineer Interviews
If you have any questions about Amazon coding interviews, do not hesitate to ask them below and we will be more than happy to answer them. All questions are good questions, so go ahead!
Applying for other companies? Check out our other guides for , , Microsoft, , and Airbnb software engineer interviews.
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If You Don’t Prepare For These You Will Probably Fail Your Amazon Interview
Amazon heavily emphasizes the during the interview process. They care as much about the Leadership Principle questions as they care about the technical questions. In fact, if you fail the interview and you are surprised, it’s possible that you underperformed while answering the LP questions.
Amazon is a data-driven company, so provide data for each of your explanations. Anecdotally, a common reason that SDE candidates fail the LP questions is that they fail to discuss the metrics or impact when explaining their answers. You can avoid falling into this trap by using the STAR framework.
Practice Questions For The Amazon Interview
Interviewing for a software engineering position at Amazon? Start with our practice programming interview questions. We’ve helped several engineers get the job at Amazon already.
“Our questions are behavioral-based and focused on assessing for fit. I encourage candidates to give examples that show how they can follow an inquiry and get to the root cause of something.”
Miriam Park, director of MBA and university recruiting at Amazon
“It’s fantastic being so close to a product where we can see how it impacts the actual customers.”
Chelsea Krueger, senior principal engineer at Amazon
Want more coding interview help?
Check out interviewcake.com for more advice, guides, and practice questions.
Actually, we don’t support password-based login. Never have. Just the OAuth methods above. Why?
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Reverse Words In A Sentence
Reverse the order of words in a given sentence .
To solve this problem, well keep an array of size amount + 1. One additional space is reserved because we also want to store the solution for the 0 amount.
There is only one way you can make a change of 0, i.e., select no coin so well initialize solution = 1. Well solve the problem for each amount, denomination to amount, using coins up to a denomination, den.
The results of different denominations should be stored in the array solution. The solution for amount x using a denomination den will then be:
solution = solution + solution
Well repeat this process for all the denominations, and at the last element of the solution array, we will have the solution.
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Hiring Decision Process For Amazon Software Development Engineer Interview
This step is called the Debrief. Interviewers make notes in each round and mark candidates as Strong Hire, Hire, No Hire, or Strong No Hire.
Unlike, in the Amazon SDE interview process, you have to pass each round to qualify for the next one. Notes about your evaluation are filed after every round. In the debrief, all these notes are combined with the Bar Raiser evaluation to decide whether you are a good fit for Amazon or not.
We suggest you read for more insights on the Amazon hiring process.
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Interview Questions And Answers
There are a number of questions that you should have answered prior to your next interview. You need to understand what motivations are driving your job search. You should know what kinds of questions an interviewer is likely to ask you, and what level of importance is applied to your answers to various questions and question types. While a Java developer would expect to see core Java questions, and a .Net developer would expect to see core .Net questions, there are a host of other topic areas that are important to the interviewer. You will find the following included in this book.
- Questions you should ask yourself when thinking about a job switch.
- Questions to ask your interviewer to help determine the organizational health of your potential employer.
- Characteristics of a great software engineer.
- Essential software engineer skills and competencies, both coding and non-coding related.
- The types of interview questions you may encounter.
- Checklist to help you prepare for your next interview.
- Interview questions you may be asked, and what the interviewer is looking for in your answers.
- Questions you should ask your interviewer, and the answers you should be looking for.