r/CS_Questions • • Jun 04 '23

[Resource] Leetcode Editorials and Premium Problems

110 Upvotes

Below is an exhaustive collection of leetcode editorials (premium-only solutions) and premium problems.

Leetcode premium is expensive and inaccessible, so I hope this helps. Enjoy!

Repo: https://github.com/akhilkammila/leetcode-screenshotter


r/CS_Questions • • Oct 14 '18

CS Internship Interview Guide

79 Upvotes

First and foremost – If you are currently in college, and your college has a career related office then you NEED to be in contact with them. They can offer support such as helping you with your resume, interviewing skills, and even finding potential employers. My college’s career office also provided feedback at the end of the semester from the employers you have interviewed with so you can hear about what you are/were doing right/wrong.

 

Resumes.

 

If you have never written a resume, or want some casual reading, then I recommend: https://www.thebalancecareers.com/top-resume-writing-tips-2063314

 

The main concept with your resume is that you want to associate the business needs with your own skill set. Below is a brief description I took from a company I found online.

• Super solid skills in multiple object-oriented and front-end languages (Java, C#, .NET, Ruby, Angular, JavaScript, Ember, etc.) and a drive to hone their craft and develop new skills.  

•Practice getting their hands dirty in Agile development practices including test-driven development (TDD), continuous integration and pair programming.  

• Superhero powers in consulting, collaboration and communication.  

•Experience cranking out mobile applications and desktop solutions in true Agile environments.

 

Now, I don’t know about you, but I rolled my eyes so hard that I temporarily went blind when I read, “superhero powers in consulting.” Ignoring my pain temporarily; I would like to instead, break down what they would like to see on a resume.

 

Languages – You may want to indicate somewhere on your resume what languages you have experience with, and the skill level associated with it. You want to make sure that if you know what they are asking for, then it's on your resume, even if it has been a few years since you have programmed in that language. At this point, it is all about getting the opportunity to get in front of the employer. You can always take a crash course to freshen up on that language between now and your scheduled interview time. ** I was proofreading this before posting, and I want to make this clearer. Do NOT lie about the fact you know a language or architecture; rather, I am saying you should not omit the fact that you have had experience with it. **

 

On your resume, you may have an area with work experience or projects, and in that area, I would try and include key phrases to show you have experience with their other criteria:  

  • Created an android application in an Agile environment utilizing Test Driven Development.

  • Outstanding written and verbal communication skills.

  • Supervisor, Shift Leader, Key Holder, etc. at XXX job.

  • Entrusted with the task of XXX.

 

Doing this is not only important but mandatory. You should not have a “one-size fits all” resume. When I hear that someone has applied to a large number of positions and never got a call back my initial thought is that they are not tailoring their resume to the position. This part may be hard for a traditional college student as they typically have less work experience, but this is where projects come into play.

 

Your resume should include other items such as your major, college, GPA (if >= 3.0), expected graduation date, and your contact information. You can also list other key facts like what clubs you are apart of, your minor or dual major, and potentially volunteer activities (if you have space to fill). Remember you a college student so your education information should be at or toward the top of the page not at the bottom.

 

Your resume should not include items such as your high school information, unrelated hobbies, photographs, the date, or the phrase, “References Available Upon Request.”

 

Projects

 

Projects are important, and I do encourage you all to pursue them. There are giant project listings on Reddit and other various sites. The only thing holding you back is yourself, and you need to stop doing that. Employers want to see you are doing more than just attending class. I would also encourage you to think of a minor problem in your life and turn that into a coding project. You can then work on that project(s) utilizing different development styles to get some experience with them. If you are proud of that project, then you should get feedback on it to see if you can improve it or even broaden its scope. Once completed I would encourage you to upload it to Github. ** Note: you can upload unfinished projects to your page, it's just my preference to only upload completed ones… Maybe that’s why I have so few uploads…).

 

Github

 

I have NEVER been asked if I have a Github page. However, I have been asked about extra activities that I participate in, and that is where Github can become a powerful tool. Being able to show a potential employer your coding style, and various projects can be beneficial or damaging depending on how you manage it. I have two accounts. One that is professional and that is listed on my resume where I store completed projects, and one for work in progress or silly projects that I don’t want them to see.

 

Interview Preparation:

 

DO:

 

  • Go through the company website, and jot down key facts that you think may be important to you later on.

  • Research the company through other websites such as glass door. Take what you read with a grain of salt but sometimes the information there can be invaluable.

  • Research the community that the company resides in, and the impact (if any) that it has had there. This is harder to do in larger cities, but super easy to do in smaller ones.

  • Print copies of your resume, on resume paper, and place them in a nice envelope or binder to bring with.

  • Research and write down a few interview questions on a dedicated page for that company in said binder. NEVER have anything else regarding that company or any others in the binder. It should be clean and simple and for this one purpose only. When you are done with that company interview, you can tear out those pages, remove your resume copies, and put them elsewhere so you can start again if needed.

  • If applicable you should do a test drive on how you are going to get to that company. You can’t always do this but when you can it is nice as it relieves the stress of getting there.

  • Eat smart the day before / during

  • pack a water bottle, and a pencil.

  • Clean your vehicle before you go to an interview. I have heard and read about hiring managers walking people out to their car to see if it is clean as that can tell a lot about a person.

  • Prepare an elevator speech about yourself.

  • Study the notes you took earlier the day before/day of the interview.

  • Basic Hygiene the day before, and day of.

  • It is ALWAYS better to be overdressed than underdressed.

  • Get there 5 – 10 minutes early.

  • Be friendly to everyone when you get there.

  • Look up common language interview. Do they program in C#? If so I’d search by, “C# Common Interview Questions.”

  • Look up common interview questions in general.

  • PRACTICE YOUR ANSWERS

  • PRACTICE YOUR ANSWERS

  • PRACTICE YOUR ANSWERS

 

DON’T:

 

  • Think that researching them is useless. In almost all my interviews they have asked me to tell them about the company, and why I wanted to work there.

  • Forget to bring extra resume copies.

  • Eat unhealthy day of the interview.

  • Show up late, or arrive more than 10 minutes early. It says a lot about you and time management skills.

  • Be rude to anyone when you arrive.

  • Think you can ‘hold it’ until the interview is over.

  • Forget to brush your teeth

  • Forget to bring breath mints

 

Interview

 

Remember that interviews are both for you and the company. If you ever go through an interview that gives you a feeling you don’t like then make a note of that because usually, your gut feeling is correct. If they can’t sell you in an interview (and vice versa), then you will hate working there.

 

With that said, you should know that there are two types of interviews that I have experienced. What I like to call the “Pre-Test Interview” and then the actual interview itself.

 

The pre-test interview is usually made up of some form of math, or logical quiz to gauge your skill set. Most of them have been relatively straightforward, such as following some variables through a loop and writing down what is happening at each iteration; to filling in a flow chart based off the next sequence of steps. Once that is done they will then escort you back to where they conduct the actual interview.

 

Interviews usually follow a simple pattern that once you learn it will be easy to spot. You get in the room, and the people who are interviewing you will introduce themselves, and follow that up by asking you to do the same. Do you remember that elevator speech I mentioned above? Well, this is where it comes in handy.

 

Once the introductions are done, they will dive right in asking you a bunch of questions that can range from technical too, “tell me a time when…”.

 

At this point, my best advice is to take a deep breath, sit up straight, and try to relax. You remember that water I mentioned you should bring? Take a sip of that. If you get asked a question you don’t know then your response should never be “I don’t know,” or worse yet, “Yeah I know that.” Instead, you should be honest while providing information.

 

For example, if you don’t know how to code the Fibonacci sequence, you shouldn’t try nothing and say, “I can’t.” Rather, you should look at the problem and realize it requires a loop and some variable declarations. Maybe write what that would look like on a sheet of paper, and try to work through the steps. If you can’t then I would explain what you did try, and why you attempted it that way. Some interviewers aren’t always looking for the right answer, but rather what you do when you don’t know the answer.

 

Toward the end of the interview, they will open it up to you so you can ask them questions. At this time you can look at the questions you wrote down prior and reflect on if they are worth asking. This is not the time to talk about money, or benefits as that can happen when they offer you the position. Do not ask them questions that they already answered, which is why you need to be an active participant in the interview, and if you hear them answer one of your questions then place a small check mark next to you it so you can ignore it when the time comes. I would encourage you to make quick notes throughout if it interests you; or if they say something you want them to elaborate.

 

Your last question, if you are still interested in the position, is to re-state that you are still interested in the position, and to inquire what their interviewing process is. How long are they going to be interviewing for? When will you hear back? When you leave, you should still be friendly to everyone on your way out. Drive smart as you leave as they can still be watching. Within the next 24 hours, you should send them an email thanking them for there time.

 

Sample Email

 

Dear (PERSON),

 

I enjoyed meeting with you the other day and discussing all that (YOUR COMPANY) has to offer. I truly appreciate you taking the time out of your busy schedule to (COME TO MY COLLEGE OR TO SEE ME) to interview me for the role of a (POSITION – INTERN).

 

I believe that my (1 – 2 SKILLS) make me an ideal candidate for this position as I bring (1 -2 PERSONALITY TRAITS).

 

After our interview, I am even more interested in this position. The information you shared (SUCH AS THAT SUPER INTERESTING FACT I WROTE DOWN IN THE INTERVIEW) matches well with my achievements and goals.

 

Thank you for your consideration for this position,

 

(YOUR NAME).

 

Then you have to wait. If a company says they take two weeks to respond to you, then I would way until the middle of the third week to reach back out to them to check in and see if they have any updated timeframes for a decision.

 

There is more that I wanted to say, but I think I have been distracted long enough for today. So I have included some questions that you can expect to answer in an interview. Best of luck all!

 

COMMON INTERVIEW QUESTIONS

 

  • Describe a time in which you overcame a challenge in a group setting.

  • Describe a time in which your program was not working as intended, what did you do?

  • What percentage of coding/testing do you think is acceptable?

  • How do you handle stress?

  • Describe yourself.

  • Where do you see yourself in 3, 5, 10 years?

  • What is polymorphism?

  • What is method overloading?

  • What is special about the final class?

  • What is the difference between an abstract class and an interface?

  • What is the difference between equals () and == ?

  • Why should we hire you?

  • What do you consider to be your weakness?

  • Tell me about a challenge or conflict you've faced at work, and how you dealt with it.

  • What type of work environment do you prefer?

  • What do you want out of this internship?


r/CS_Questions • • May 10 '22

[Resource Sharing] Leetcode Company-wise Problems Breakdown for 2022

60 Upvotes

Below are lists of updated company-wise questions available on Leetcode Premium with their solutions. I personally purchased Leetcode Premium just for this information, and I think is appropriate to share this community-contributed information back with the community. There are similar, outdated (the last update was 2 years ago) projects, but this one is fresh out of Leetcode. Cheers.

Repository: https://github.com/hxu296/leetcode-company-wise-problems-2022

Company List:

  1. APT Portfolio

  2. Accenture

  3. Activision

  4. Adobe

  5. Affirm

  6. Airbnb

  7. Akamai

  8. Akuna Capital

  9. Alation

  10. Alibaba

  11. AllinCall

  12. Amazon

  13. American Express

  14. Apple

  15. Arcesium

  16. Arista Networks

  17. Asana

  18. Athenahealth

  19. Atlassian

  20. Baidu

  21. Barclays

  22. BlackRock

  23. Bloomberg

  24. Bolt

  25. Booking

  26. Box

  27. ByteDance

  28. C3 IoT

  29. Canonical

  30. Capital One

  31. Cashfree

  32. Cisco

  33. Citadel

  34. Citrix

  35. Cohesity

  36. Commvault

  37. Coursera

  38. Cruise Automation

  39. DE Shaw

  40. DJI

  41. DRW

  42. Databricks

  43. Dataminr

  44. Dell

  45. Deutsche Bank

  46. Directi

  47. Docusign

  48. DoorDash

  49. Drawbridge

  50. Dropbox

  51. Druva

  52. Dunzo

  53. Duolingo

  54. Epic Systems

  55. Expedia

  56. FPT

  57. Facebook

  58. FactSet

  59. Flipkart

  60. Gilt Groupe

  61. GoDaddy

  62. Goldman Sachs

  63. Google

  64. Grab

  65. HBO

  66. HRT

  67. Honeywell

  68. Hotstar

  69. Huawei

  70. Hulu

  71. IBM

  72. IIT Bombay

  73. IMC

  74. IXL

  75. Indeed

  76. Info Edge

  77. Infosys

  78. Intel

  79. Intuit

  80. JPMorgan

  81. Jane Street

  82. Jeavio

  83. Karat

  84. Leap Motion

  85. LinkedIn

  86. LiveRamp

  87. Lyft

  88. MAQ Software

  89. MakeMyTrip

  90. Mathworks

  91. Mercari

  92. Microsoft

  93. MindTickle

  94. MindTree

  95. Moengage

  96. Morgan Stanley

  97. National Instruments

  98. Netflix

  99. Netsuite

  100. Nuro

  101. Nutanix

  102. Nvidia

  103. OT

  104. Opendoor

  105. Optum

  106. Oracle

  107. Palantir Technologies

  108. PayTM

  109. Paypal

  110. PhonePe

  111. Pinterest

  112. Pocket Gems

  113. Postmates

  114. Pure Storage

  115. Qualcomm

  116. Qualtrics

  117. Quora

  118. Rakuten

  119. Reddit

  120. Redfin

  121. Riot Games

  122. Robinhood

  123. Roblox

  124. Rubrik

  125. Rupeek

  126. SAP

  127. Salesforce

  128. Samsung

  129. Sapient

  130. ServiceNow

  131. Shopee

  132. Snapchat

  133. Softwire

  134. Sony

  135. Splunk

  136. Spotify

  137. Sprinklr

  138. Square

  139. Sumologic

  140. Swiggy

  141. T System

  142. TIAA

  143. Tencent

  144. Tesla

  145. Thumbtack

  146. Tiger Analytics

  147. Toptal

  148. TripleByte

  149. TuSimple

  150. Twilio

  151. Twitch

  152. Twitter

  153. Two Sigma

  154. Uber

  155. United Health Group

  156. VMware

  157. Valve

  158. Virtu Financial

  159. Visa

  160. Walmart Global Tech

  161. Wayfair

  162. Wealthfront

  163. Wish

  164. Works Applications

  165. Yahoo

  166. Yandex

  167. Yelp

  168. ZScaler

  169. Zenefits

  170. Zillow

  171. Zoho

  172. Zomato

  173. Zoom

  174. Zopsmart

  175. eBay

  176. edabit

  177. instacart

  178. payu

  179. peak6

  180. persistent systems

  181. razorpay

  182. tcs

  183. tiktok

  184. zeta suite


r/CS_Questions • • Dec 29 '16

350+ Data structures programming interview questions

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techiedelight.com
44 Upvotes

r/CS_Questions • • May 09 '19

Why do tech company like Facebook and Uber need so many developers?

34 Upvotes

I have always wanted to ask this question, it sounds stupid but here me out. Uber and Facebook employee about 2,000 developers each. To the best of my knowledge Facebook only has Facebook for mobile and a website. Also isn't Facebook basically a finished product? What coding do developers have to do for something which is finished? Also, Uber only had a mobile application. It is also a finished product. So there a thousand developers working on one app? Maybe this is a stupid question and I don't have enough industry experience (only one software internship). Can someone please explain? When I interned as a software developer I finished one project over the summer. Once it was completed that was that. Idg how fb needs so many developers for a complete product?


r/CS_Questions • • Jul 22 '20

what has been the most frequent technical question/coding challenges you have been asked to do?

29 Upvotes

I am based in the UK.

Mine has been the followings in order of most frequent to less frequent::

Finding target in Maze: used DFS, Dijkstra, A*

Roman numeral converter

Fib and Fizz buzz

For technical questions I received the followings in order of most frequent to less frequent:

What is SOLID

What are race conditions ? what is Deadlock?

When did you use indexes in the Database? why? pros and cons of indexes

what is the definition of microservices? ( I don't know an acceptable answer to this one appreciate an answer!)

what are integration tests?

React/Redux specific:

what are middlewares in Redux?

how do you render only part of you react based page? ( selectors?)


r/CS_Questions • • May 19 '25

Job hunting as a senior dev is destroying my confidence

27 Upvotes

Don’t know if I’m posting this to rant, seek validation, or just vent into the void, but I’d love to hear others thoughts on the current state of the job market and interviews.

Quick background: I’m 28M, been working in the field for about 11 years. Over the years I’ve touched a wide range of technologies — Node.js, PHP, Spring, Django, React, Angular, Next.js, Android, iOS, Windows Phone (yeah), Flutter, Ethereum, Solana, Unity. You could say I’m a jack of all trades, master of none. But I’d say I’m solidly senior in at least React and Node, and I have a track record to prove it (production running code in all of those stacks).

Here’s the issue: the job market and the way interviews are done right now feel completely broken. I feel like a monkey juggling, just to get rejected. I don’t mind doing coding challenges or technical interviews, but when there are 5+ rounds, multi-day home assignments, and no feedback at all — it feels like a huge waste of time and energy.

Even when I go through all the hoops, with a portfolio to back me up, I still get ghosted or receive a generic rejection. And in the rare cases I make it to the final stage, the offer is often way below market not even close to what’s fair. What’s worse is that sometimes the whole process was initiated by the company’s own HR team.

This has been going on for about half a year now. I try not to let it get to me, but honestly, it’s been eating away at my confidence and mental health. I am destroying my brain in order to improve, to learn more, to get better but no matter what, I still feel like I’m just not enough.

To be clear, this isn’t a cry for help. I’m currently the head of IT at a random company (though I’d like to change jobs) and doing okay financially. But emotionally/mentally I’m drained. Just wondering: Is anyone else feeling this lately?


r/CS_Questions • • Jan 07 '21

My question is where are the ACTUAL entry level jobs out there? You know, for people like me who literally just graduated last month and has exactly 0 professional experience or internship experience in anything related to computer science.

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27 Upvotes

r/CS_Questions • • Jun 25 '18

~350 programming interview problems that are being asked in interviews, ranging from data-structures, algorithms, system design, DB and puzzles

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27 Upvotes

r/CS_Questions • • Aug 01 '22

I created an Algorithm to try to predict Google Interview Questions

26 Upvotes

Hi CS folks,

I created this open resource / website around 2 weeks ago to help people prepare for Google interviews. It uses a very simple algorithm to figure out relevant LeetCode Questions to practice. With luck, maybe it helps someone here =)

Additionally, I collected a ton of YouTube video material to build two Courses (also as an open resource) on Interview Preparation and System Design. I checked in with both the main creators of the Courses (GKCS and Jeff H. Sipe) and they like it ☺️

I would super appreciate any feedback. Bad feedback is the best, it helps refine the resource to be even better. So far, the list has surprisingly already matched a few Questions asked in Interviews (confirmed by Googlers who reached out to me)

https://alphabet150.com

Hope I can help a few of you with it!


r/CS_Questions • • Feb 22 '22

Spaced Repetition LeetCode Practice Web App

26 Upvotes

Hey guys– Amazon SDE here,

A few months ago I built a basic command line tool to let me do spaced repetition style practice with LeetCode problems, and found it to actually be really effective for my memory and overall comprehension, so I decided to build it into a full web app. Basically it has a list of LeetCode problems and serves as a framework where you can practice problems, give yourself a score from 0-5 based on how you did, and it will determine how long you should wait until you review it again (worse scores ⇒ short wait, good scores ⇒ longer wait). This all gets distilled into a “daily review” which collects all the problems up for review for that day. In its current, very early implementation it only includes the Blind75, but I plan on expanding it in the near future.

I’ve been using it myself for about a week trying to spot bugs, but I figured sooner or later I’d have to just put it out there. It’s still a work in progress, so I’m sure there will be bugs, but I’d love for anyone that’s willing to give it a try, I think you’ll find it to be a pretty useful tool (especially in today’s job market). Accepting of any and all feedback, thanks!

https://codellama.dev

Feel free to use this demo account login if you want to try it out before setting up your own:
e: [email protected]
p: twosum


r/CS_Questions • • Jan 26 '21

In light of the insanity of gamestop's stock, how does Robinhood serve up real-time and heavily fluctuating data to millions of users at once?

25 Upvotes

This morning, GME had about 75M of volume listed on robinhood in about 20 minutes of trading. That's about 66,000 shares being traded per second on this brokerage itself. If you assume 100 people/readers pulling up the stock page for every share traded, that's 6.6M page GETS per second.

Obviously there is an entire industry devoted to exactly this, but it would be interesting to bounce ideas on how this is accomplished. Some thoughts:

• The volume metric shown is eventually consistent, sharded in something like Google datastore?

• The price must come from a central source of truth (the stock exchange) which must serve it to brokerages around the world. Perhaps via a push model? websockets?

• A CDN cannot be used, since this info is not cacheable. However, a lot of the items on the page can be cached - the stock symbol, name, your holding and cost basis, the P/E and other stats. So would it then be making an API call for the static data and get that from CDN, and another API call for the dynamic data? For the latter, it's probably some kinda on going stream API?


r/CS_Questions • • Mar 15 '17

How NOT to design Netflix in your 45-minute System Design Interview?

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hackernoon.com
25 Upvotes

r/CS_Questions • • Jan 18 '16

Coding interview study sheet

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github.com
25 Upvotes

r/CS_Questions • • Mar 09 '16

Steps to solving a technical interview question

23 Upvotes

Successfully answering most technical interview questions comes down to the following: “First solve the problem, then write the code.” The first thing that most candidates will do after hearing the question is take the marker, turn to the whiteboard, and write,

function (var a , var b) {

DO. NOT. DO. THIS. It takes serious effort to break this habit but it is essential to remember that a successful answer is not at all dependent on producing functioning code. In fact I can't remember the last time I actually ended up coding a solution to the problem during an interview. Instead, let me give you a simple pattern for working through these problems:

Step 1: Define the problem input/output Most interviewers want to see that you take time to understand the problem before diving in. The best way I know of to do this is to repeat back your understanding of the problem and to clarify the input and output of the [in most cases] function. Make sure you understand what your input looks like. If it's a string make sure you know if there's whitespace, capital letters, if it's ASCII encoded, etc. If it's a number make sure you know if it's an integer what the range of possibilities are. Ask if you need to worry about validating the input or if you can assume it follows the given rules. Likewise make sure you understand what format your return value (or however you're getting the data back out) should be in.

Step 2: Come up with a few examples Start with the first example to come to mind no matter how trivial. Define an example input and what the output should be. If there is something you don't understand the interviewer will correct you and that won't count against you. So many times I've seen the candidate start out solving the wrong problem or with some important misunderstanding. Of course I don't let them carry on for long without correcting them but it's much better to catch these on your own so a big part of these first two steps is simply understanding the problem.

Now come up with a few more examples. Try to think of some examples that might pose some tricky problems. For example try an empty array, try multiple of the same value, negative numbers, or other things that might not seem obvious. The tricky cases won't always be obvious but if you can get one or two it will help you as you work through the problem.

Step 3: Come up with an algorithm Now that you have a solid understanding of the problem and some examples to guide your thinking, start the problem solving. I can't give you a lot of help with this but make sure that you communicate your thought process as clearly as you can. Draw pictures, ask questions out loud, make sure it's clear to the interviewer what's happening in your mind. Don't be afraid to make mistakes or start down the wrong road - that's how solving tough problems goes. Many times if I have no idea how to get going I'll say, “well the first solution to come to mind” and then lay out an O(N!) solution or talk through one I can already see won't work but can at least serve as a starting place. When you're done with this step you should have an algorithm that solves the problem. Note that this isn't code. Most of the time my solution ends up as a kind of bullet pointed list of pseudocode-y steps. Your natural reaction at this point will be to either start coding or to cap your marker and say, “well there you go.” Resist both of these urges.

Step 4: Test your algorithm Take your newly formed algorithm and run all of the examples from step 2 through it to make sure you get the output you expected. The last thing you want to do is finish with a solution that fails one of your own test cases. This will often reveal some kind of problem or loose end you've forgotten to tie up. Not a problem - return to step 3 and rework your algorithm. You want to find these problems before you've declared that you've finished. Once your algorithm passes your test cases and you're confident that it's a correct solution say to the interviewer, “I think this solution works, would you like me to code it?”

Most of the time they won’t ask you to actually write code - they're interested in your thought process and they know you can write code if given the solution to a problem. If they do, your algorithm should be sufficiently detailed that it will be easy to quickly code it up. Another possibility is that your interviewer will point out a flaw in your solution, ask about a case you missed, or ask if there's a more efficient way of going about it. Don't get flustered by this - it is certainly not an indication that you did poorly or that you won't get the job. Answer the follow-up questions. Turn it into a discussion applying what you know and you'll probably even learn something.

Throughout answering a technical question make sure to use your interviewer as a resource. Treat it almost like a group brainstorming session. Feel free to ask them questions to clarify the problem and and even things like, “do you think that might work?” As you're working through your solution. It will put both of you at ease and make it easier for them to guide you to the solution if needed. The most important things you can do are keep at it no matter how stuck you get and think out loud so the interviewer understands your thought process. Sometimes you won't get the solution and that's okay. I've interviewed multiple times at the same company and completely aced the interview and gotten the offer despite failing miserably in the first round on another occasion. There's some luck in the question and interviewer you get so just do your best with what you're given.

Now to practice. The key here is to get into the habit of following this four step pattern whenever you go to solve a coding problem. (It's a great pattern for actual coding as well I might add.) A good resource for this are sites like spere online judge these are short challenges, many of which are very difficult without having done any similar problems. Grab a whiteboard or a piece of paper, pick a problem you haven't seen and use it as practice to follow the steps while thinking aloud. Film yourself if you can and watch it back. You'll be surprised at the things you notice.

The essential though is getting used to following the four steps as you work to a solution. These steps will keep you out of the major gotchas and the rest comes down to your CS foundation. Improving that is outside the scope of this write-up but there are tons of online resources to help you. Remember that the interviewer is concerned with your ability to reason and work to a solution of a difficult problem. You can do well in an interview despite needing prompting to find the answer or even without ever having found the best solution.

Remember: Solve the problem, then write the code.


r/CS_Questions • • Feb 12 '16

Can you score an onsite at Google/Uber or LinkedIn? This is a compilation of 10 phone screen interview questions (with solutions).

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22 Upvotes

r/CS_Questions • • Mar 23 '21

Why are NoSQL DBs recommended for scaling when relational ones are able to partition as well?

21 Upvotes

As I go thru Grokking the system design, I notice that it likes to recommend Cassandra to scale and shard the data.

However, you can partition data in RDMS like MySQL as well. You could use a date range as the partitioning scheme and for a large DB, maybe have a partition per month. I considered that this has to be implemented on the application level, introducing obvious overhead and complexity. However, AWS supports this for their RDS offerings out of the box with some tweaking:

https://aws.amazon.com/blogs/database/sharding-with-amazon-relational-database-service

Do relational integrity constraints such as foreign key, primary key, joins etc come in the way of effective partitioning?

What's the difference between Cassandra partitioning data with consistently-hashed nodes and MySQL/other RDMSs with partitions?


r/CS_Questions • • Dec 31 '16

Google internship interviews, my experience and a few tips

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21 Upvotes

r/CS_Questions • • Jun 24 '17

I was an mock interviewer for Gainlo, a service for getting coding interviews from people at Google/Amazon/Facebook/etc. I discourage the use of Gainlo. Skip the middleman, there are lots of folks willing to interview you for free or at least cheaper. AMA.

20 Upvotes

TLDR

I don’t recommend Gainlo, and I will be happy if you use anyone but Jake. Yes, I do offer mock interviews.


About Me

I’ve worked at FAANG companies for most of my software engineering career and built a software engineering curriculum for a bootcamp. I tried being a mock interviewer with Gainlo for a short while as a side hustle but I realized it wasn’t a trustworthy environment.

Since then, I’ve run >1000 coding & system design interviews since 2012 and know how to educate others deeply about software concepts.


My Experience w/ Gainlo (Mocki.co)

I was an interviewer for this company/guy for a couple of weeks to test the waters, see how it operates, and if it was legitimate. The appeal of Gainlo is supposed to be that your interviewers are FANG engineers and get risk-free feedback. The person/group behind Gainlo, “Jake”, acts as the middle-man and matchmaker for candidates and charges $300+.

There were 4 main problems with this:

  1. Inconsistent/Low-quality interviewers: A friend was quoted $300 for an entry-level interview by Jake. For perspective, I was paid $75/hr after negotiating. I doubt you’ll get a good, verified, professional interviewer if he is willing to take that small of a cut.

  2. Questionable authenticity of interviewers: All it takes for someone to be an interviewer is to send Jake a LinkedIn profile from a convincing e-mail address that matches that person’s profile name.

  3. The interviewer’s performance doesn’t matter: Your interviewer can be complete crap, and that’s your loss. Jake doesn’t assess the people he works with. He just wants to pocket his share and get out of the equation. In the link above, that indifferent interviewer still got paid for doing nothing for you.

  4. No professionalism: There’s no refund policy. He pays interviewers when he remembers rather than on a schedule. He scheduled me for times that I explicitly said I was unavailable. He’s very disorganized.

They are taking a huge cut for playing matchmaker when people could instead be getting interviews for free or at least get bids on Reddit forums for mock interviews. Even if you don’t use me, I’ll be happy if you don’t use Gainlo.


Free Resources

If you’re not ready for mock interviews, there are so many free practice coding exercises available: /r/CSCareerQuestions, /r/CS_Questions, /r/AskComputerScience, /r/ComputerScience, /r/learnprogramming, https://www.pramp.com (Peer-2-Peer), https://www.interviewbit.com, LeetCode, InterviewCake, HackerRank


Are you still doing mock interviews in 2024?

Yeah, you can book with me on my Calendly page, no payment upfront. Be ready for real, honest feedback!


Success Stories

I’m not a substitute for hard work and dedication, but I can help you get unstuck and gain momentum by identifying and addressing gaps. My clients worked long and hard to land these offers.

# of SessionsBackgroundOffers (1st entry = accepted)
93yr mechanical engineerentry-SDE@GOOG, AMZN, MSFT, SNAP
710yr data scientist w/ Ph.DPrincipal@FB, GOOG, Airbnb + 3 more
44yr data scientistMachine Learning@FB, junior SDE@Instacart + 2 more
32yr front-endentry-SDE@FB, GOOG
3college-gradentry-SDE@Bay Area startup
25yr SDEPrincipal(65)@MSFT
23yr data engineerSDE1@AMZN
2college juniorIntern@LinkedIn then entry@FB, GOOG
16yr SDEL5@Square
1boot campentry-SDE@GOOG
1college-grad + boot campentry-SDE@Los Angeles startup
12yr back-end engineerentry-SDE@Twitch, TWTR, Playstation

Notes

gainlo sucks gainlo is a scam gainlo scam gainlo bad gain lo scammer


r/CS_Questions • • Aug 17 '25

what yall think? 💥🔥

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19 Upvotes

I think my resume is decent but I'd appreciate yall opinions on it. if there is something I can improve please let me know feedback is how I can improve it

I’ve been working on refining my resume and I think it's decent. That said, I know feedback is from other is important so if anything stands out good or bad, I’d love to hear it! Appreciate the help!


r/CS_Questions • • Feb 09 '21

I have been asked this question in the interview at JP Morgan, my friend has been asked this question during the interview at Amazon. A lot of other companies also ask this question. It is Leetcode 20. Valid Parentheses (Java)

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19 Upvotes

r/CS_Questions • • May 03 '19

A collection of common interview categories, interactive code snippets, and tips

19 Upvotes

Article here

A common issue I see with folks I mock interview is that they either have a good understanding of algorithms and struggle with implementation or they have the opposite scenario. To help bridge this gap, I wrote this article. It contains mental recipes and interactive code skeletons for a few algorithms. Methodology like this got me multiple offers from BigN/FinTech/Unicorns, so I hope this helps the community.


r/CS_Questions • • Mar 26 '24

I suck booty at math but want a career in programming. What should I do???

18 Upvotes

I tried posting in r/cscareerquestions but my acc isn't at least 7 days old so I'm asking here.

I (15) love to code. I'm the only person in my online school taking the informations technology class and its really cool. I have tinkered with some different languages including, lua (roblox), html and css (neocities), and am attempting to learn JavaScript to hopefully make a mobile app. With my love of coding I wondered if it would make a good career, tech is an ever growing industry and ppl in tech often make amazing salaries. The shitty thing is, I cannot do math to save my life. Well, if that's a bit of an overstatment. I can do math its just borderline impossible to wrap my head around without my mom explaining it to me one-on-one. After I understand I do it quite well. I also can't remember past math units I've done for shit. I've been doing geometry for 2 years now (and its been ROUGH lemme tell ya) and did algebra from I think 6th-8th? Maybe 7th-8th, (I'm a sophmore). If I were to be tested on algebra topics now I would probably do horrificly. I want to make a career in programming sososososo bad but I'm worried my dog water math skills dismantle that dream completely. What should I do? Are there any programmming degrees that require little to no math? Or at least nothing too hard? Thank you so much 😭🙏


r/CS_Questions • • Jul 18 '21

[Interview] How to go about preparing for an API Design Interview?

17 Upvotes

Design an API for a customer-facing app that is easy to integrate with, flexible to evolve and scales assuming massive customer traffic.

Take into account also it being sympathetic to integrators and users.

Can it be designed differently to simplify the dev's code?

I've not done one of these before. In my personal experience, I've dealt with a lot of REST APIs, and I understand the advantage of that - stateless, scalable, designing with HTTP verbs in mind (e.g. GETs can be cached, and then a PUT to the same endpoint can be used to invalidate).

Also, what does it mean by Easy to extend. What does extending an API allude to?

Any other tips/docs I could read?


r/CS_Questions • • Feb 06 '21

Want to share Interview Preparation Courses

17 Upvotes

I have organized some of the best interview preparation courses like:

  1. AlgoExpert

  2. SystemsExpert

  3. Epic React Pro by Kent C. Dodds

  4. Grokking OOD

  5. Grokking The Coding Interview

  6. Coderust: Hacking The Coding Interview

  7. Grokking Dynamic Programming Patterns

  8. Grokking the System Design Interview

  9. ZeroToMastery: Master the Coding Interview Big Tech (FAANG) Interviews

  10. Gaurav Sen: System Design

  11. TechSeries dev: AlgoPro, Tech Interview Pro

  12. BackToBackSWE

  13. CodeWithMosh

  14. InterviewCake

  15. InterviewCamp

  16. Applied Course

  17. InterviewEspresso

  18. SimpleProgrammer

And some other courses. DM me if you are interested to have these courses.