EXTREMELY LONG POST AHEAD, I wanted to post this as different parts but fuck it. Move ahead to the middle of this post if you are solely interested on my interview experience :)

Hi everyone, even typing this out feels kinda surreal. It was my dream company, tied with google, so I couldn't be happier. I feel inclined to share my entire story from the start, since I have been on reddit from the last 7 years and feel compelled to help someone reading this out, even if it's a few years down the line.

So about myself first, I am a 3rd year circuital student from an old iit, general male. I come from a lower middle-class family, had just enough to give a decent life but not a lavish one. My parents sent me to a coaching institute thinking it was a boards tuition center, they never had any expectations but during covid since i had nothing to do i fell in love with math and physics (fuck you chemistry). Rest is history.

After joining college, I literally did not study at all for the first 1.5 years. Got a gf, broke up with said gf within 2 months, drank, smoked, played poker with real money, played video games and went to gym every day for this entire duration. This led me to getting a sg of less than 7 in a sem, which I deeply regret, fucked up my overall cg to this day.

Towards the end of 4th sem my cg was just above 8, and I realize that I have to actually study for internships. Prior to this I have not done dsa at all, and the only experience I had with coding was the introductory C course. After talking to a lot of seniors about what to do, they said that the summer is enough to complete dsa and crack good software companies. So i locked in for the summer, did not put in this much effort ever since jee.

PREPARATION:

Completed Strivers A2Z sheet from the ground up. Please try solving the problems on your own and only if you cant solve it after decent effort go for the video, if you can solve the problem then great! You can skip the video. Completing this sheet is more than enough for 99% of coding assessments and interviews, except for some extremely unfair companies.

(IMP) Make use of AI: Definitely helped me the most for learning so much dsa in a limited amount of time. After reading the problem, use the audio feature of chatgpt and just blurt out your initial thought process. Tell it to never give the solution to you directly but support you in your search for the solution by giving small hints. In this way slowly and steadily keep talking to it until eventually you understand how to solve the problem completely. This mimics the method of trying to solve the question on your own but is wayy faster and honestly just as efficient. This I found was very effective for DP and Graph problems, because the base for solving most of these problems is the same, but the finer details is what changes the approach to the problem.

For core cs I studied OS and DBMS from love Babbar one-shot. DONT WATCH THE VIDEOS, it is long for no reason, just take the notes attached in the description and read them on your own. WIll take you less than a week to complete both, use chatgpt to clear up doubts.

For OOP i just watched Apna college one shot and love Babbar yt videos, it helps to try implement data structures on your own to understand all principles properly. Hardly should take you a day or two to complete. Dont bother with networks for internships no company expects students to know these concepts.

Since I completed major dsa prep in 2 months, the remaining month I studied ML and DL up to transformers along with revision, which is honestly overkill but it did pay off later (coming up later).

Stat Quest is an amazing channel for this purpose, cannot recommend him enough for machine learning. I promise, you watch his 100-odd video playlist on ml and you will love the experience, he teaches it in an extremely fun way and covers everything to a decently deep level. Highly highly recommend checking him out.

Coming to projects I just browsed youtube for fun project ideas, and honestly it all depends on you. I also had a decoder only transformer implementation project, which is extremely complex and would not recommend having it here, but it paid off for me in the actual interview.

Apart from this followed and used resources from many channels on yt, just to name a few Techdose for potd on leetcode and some advanced algorithms which striver has not covered, neetcode for some initial help.

INTERNSHIP INTERVIEWS:

Okay so skipping a lot of details, I got shortlisted for 2 companies on day 0, GS and another company I shall not name. I gave in total like 6 OAs but could clear only these two. Did not crack the OA for google 💔. I'll talk about my experience with gs only and will try to mention all questions I can remember from the respective interviews.

3 rounds, all are coding basically but one interview can be either technical or hr, depends on what the interviewer feels is important. Everything on pen and paper, and you have to write the pseudocode for all questions. Even the interviewer cannot use any technology, they read questions out from a book. My interviews started pretty late, 3 hours after I was called to the venue.

ROUND 1: (20 min)

Interviewer first asked me for my introduction, then asked me about a random project, which I had built as a club head. I explained it for about 5 min, when he suddenly cut me off in between and asked me a dsa question, Trapping Rain Water - LeetCode.

Now those of you who have done dsa to a decent level know that this is a very popular problem on leetcode, so internally I heaved a huge sigh of relief as I knew exactly how to solve it. Gave the optimal solution immediately within 5 min, and interviewer then asked me to leave after I wrote the pseudocode.

Initially I was extremely worried that they might have rejected me since i gave the solution so quickly to a so-called hard problem, but my worries were soon put to rest as my name was announced as selected for round 2.

ROUND 2: (1hr 30min)

Extremely enjoyable interview. First asked for my introduction, then she asked me a basic graph question which needed a bfs traversal, akin to Rotting Oranges - LeetCode but slightly different. Then we talked about different approaches, where I also later talked about Disjoint Set Units. I think they were just checking whether I knew my graph concepts lol. Then we talked about my transformer project for 45 min. Yes 45 fucking minutes out of 90. Turns out she was an ml engineer at GS so obviously she gravitated towards that project, but I had worked on that project a lot, so I answered every single question perfectly. Daresay she was impressed too.

Now before I move on to the next half of the interview, here is what she said to me.

I look forward to see how you will perform in the next round

Yes, completely unprovoked. She basically told me I was selected for the next round before round 2 was even over! So that sent me into a completely relaxed mode and all my nervousness vanished.

Next, she asked me how I would design a large-scale application, for example bookmyshow. This required dbms knowledge and I explained her starting from my choice of database, why I would choose it, how would I scale it, yada yada. There was a case study of cab booking application in love Babbars notes so I basically copy pasted those points in my interview and she seemed satisfied.

Next came the HR questions. Ong I was asked literally every single HR question possible on earth. You name it and I promise you I was asked that. I wont even try to list the questions, but I was well prepared. One of my strong points is my good english communication, so I navigated these pretty well. I suggest making chatgpt generate a list of 40-50 possible hr questions customized to the company you are targeting, helped me a lot.

Towards the end she asked me if I had any questions and I asked her what the work assigned to me as an intern would be, and would it be a production level project.

Came out of the interview extremely happy, did not expect this even in my dreams for an interview to be this good. And sure enough I was selected for the next and final interview.

ROUND 3: (~1hr 30 min)

No introduction. Immediately was handed a piece of paper with my question and was told to start solving.

Frequency of the Most Frequent Element - LeetCode was the question. I had never solved this before, so I did not have a direction immediately in mind, so my heart sank initially. After internally recomposing myself, I realized she mentioned it was already sorted, so the solution had to be o(n). And what method could you apply in an array with o(n) easily? Thus i realized two pointer must be the way to solve, and with a little help finally devised the correct algorithm.

After this she asked me something along the lines of perfect child of binary search tree and sum of the children equal to parent, simple question but she kept adding follow ups so eventually it became as if she asked me 4-5 questions, all based on binary trees/ binary search trees.

However, since we were building upon my previous solutions it never felt too hard and breezed through it. K-th Largest Perfect Subtree Size in Binary Tree - LeetCode I think this was one of the problems we were heading towards but then stopped herself in the interest of time.

Next, she asked me about one of my projects, and the good thing was that it was based on a game, and since the interviewer was not aware of this game i spent 15 min just explaining the rules, which killed a lot of time. By the end she was satisfied with my explanation.

Afterwards a few more general questions. Why GS, why did you choose this role, where do you see yourself in 5 years etc. After this the interview was over. Towards the end I tried sneakily indirectly asking whether I would be selected which in hindsight was extremely stupid, but hey game is game.

AFTERMATH:

After coming out I got to know that I had one of the longest last 2 interviews out of everyone, and that around 6 people were on waitlist for being selected, which upon hearing my heart sank. This meant that to be selected I needed to have a strong hire from all the interviewers, otherwise I won't be selected as many people were already on waitlist.

But all was good, was told within 5 minutes that I was selected by the coordinator in the midst of a heated discussion with a friend regarding how unfair diversity hiring is lol (ladies if you are mad at me you can dm me). Now I have spent 20k on giving parties alone and more to come 😝.

And with that my interview experience ends, no DP asked whatsoever, bummer as I spent a lot of time on it. No direct OS question too. I tried to include as much as possible without getting doxed, which I am sure I will get either way but oh well. Would love to reply to your comments and talk to you guys. And I typed this all out btw :)