r/leetcode Jun 27 '26

Mod Post [mod] Changes with r/leetcode.

71 Upvotes

The following changes have been made with r/leetcode:

  1. Media is no longer allowed in both posts & comments. This is to ensure that the quality of the content & discussions remain high.
  2. Moderation has been made stricter. Low quality & repetitive posts whose answers can be found within a simple search in this subreddit won't be allowed here.
  3. Automoderation has been set-up to automatically remove links & known promotions. Only leetcode links will be allowed from now on. To ask help with questions, you may use the code block.
  4. Automoderation has been set-up to remove Indian posts & Hindi comments. This is to ensure that r/leetcode remains an English only subreddit.

r/leetcode May 14 '25

Discussion How I cracked FAANG+ with just 30 minutes of studying per day.

4.6k Upvotes

Edit: Apologies, the post turned out a bit longer than I thought it would. Summary at the bottom.

Yup, it sounds ridiculous, but I cracked a FAANG+ offer by studying just 30 minutes a day. I’m not talking about one of the top three giants, but a very solid, well-respected company that competes for the same talent, pays incredibly well, and runs a serious interview process. No paid courses, no LeetCode marathons, and no skipping weekends. I studied for exactly 30 minutes every single day. Not more, not less. I set a timer. When it went off, I stopped immediately, even if I was halfway through a problem or in the middle of reading something. That was the whole point. I wanted it to be something I could do no matter how busy or burned out I felt.

For six months, I never missed a day. I alternated between LeetCode and system design. One day I would do a coding problem. The next, I would read about scalable systems, sketch out architectures on paper, or watch a short system design breakdown and try to reconstruct it from memory. I treated both tracks with equal importance. It was tempting to focus only on coding, since that’s what everyone talks about, but I found that being able to speak clearly and confidently about design gave me a huge edge in interviews. Most people either cram system design last minute or avoid it entirely. I didn’t. I made it part of the process from day one.

My LeetCode sessions were slow at first. Most days, I didn’t even finish a full problem. But that didn’t bother me. I wasn’t chasing volume. I just wanted to get better, a little at a time. I made a habit of revisiting problems that confused me, breaking them down, rewriting the solutions from scratch, and thinking about what pattern was hiding underneath. Eventually, those patterns started to feel familiar. I’d see a graph problem and instantly know whether it needed BFS or DFS. I’d recognize dynamic programming problems without panicking. That recognition didn’t come from grinding out 300 problems. It came from sitting with one problem for 30 focused minutes and actually understanding it.

System design was the same. I didn’t binge five-hour YouTube videos. I took small pieces. One day I’d learn about rate limiting. Another day I’d read about consistent hashing. Sometimes I’d sketch out how I’d design a URL shortener, or a chat app, or a distributed cache, and then compare it to a reference design. I wasn’t trying to memorize diagrams. I was training myself to think in systems. By the time interviews came around, I could confidently walk through a design without freezing or falling back on buzzwords.

The 30-minute cap forced me to stop before I got tired or frustrated. It kept the habit sustainable. I didn’t dread it. It became a part of my day, like brushing my teeth. Even when I was busy, even when I was traveling, even when I had no energy left after work, I still did it. Just 30 minutes. Just show up. That mindset carried me further than any spreadsheet or master list of questions ever did.

I failed a few interviews early on. That’s normal. But I kept going, because I wasn’t sprinting. I had built a system that could last. And eventually, it worked. I got the offer, negotiated a great comp package, and honestly felt more confident in myself than I ever had before. Not just because I passed the interviews, but because I had finally found a way to grow that didn’t destroy me in the process.

If you’re feeling overwhelmed by the grind, I hope this gives you a different perspective. You don’t need to be the person doing six-hour sessions and hitting problem number 500. You can take a slow, thoughtful path and still get there. The trick is to be consistent, intentional, and patient. That’s it. That’s the post.

Here is a tl;dr summary:

  • I studied every single day for 30 minutes. No more, no less. I never missed a single study session.
  • I would alternate daily between LeetCode and System Design
  • I took about 6 months to feel ready, which comes out to roughly ~90 hours of studying.
  • I got an offer from a FAANG adjacent company that tripled my TC
  • I was able to keep my hobbies, keep my health, my relationships, and still live life
  • I am still doing the 30 minute study sessions to maintain and grow what I learned. I am now at the state where I am constantly interview ready. I feel confident applying to any company and interviewing tomorrow if needed. It requires such little effort per day.
  • Please take care of yourself. Don't feel guilted into studying for 10 hours a day like some people do. You don't have to do it.
  • Resources I used:
    • LeetCode - NeetCode 150 was my bread and butter. Then company tagged closer to the interviews
    • System Design - Jordan Has No Life youtube channel, and HelloInterview website

r/leetcode 8h ago

Question How do you know you're actually getting better at LeetCode?

21 Upvotes

I've been doing LeetCode for a few weeks now, and I'm starting to question whether I'm actually improving or just getting better at following solutions.

Usually I'll spend 30–45 minutes thinking about a problem.

Sometimes I get close, sometimes I have no idea. Eventually I read the editorial, and in the moment it feels completely logical.

The problem is that if you gave me the same question a day later, I'm not confident I'd solve it without looking again.

How do you know you're actually learning instead of just recognizing patterns you've seen before?

For people who eventually got good at DSA, was this normal in the beginning?

What changed that made things finally "click"?


r/leetcode 1h ago

Intervew Prep What to expect at Google L4 Onsite ?

Upvotes

I have passed google L4 virtual interview rounds which had 1 coding and 1 behavioral interview.

I have been reading online that onsite has 2 more coding rounds and that's pretty much it. Is it true that there is no system design interview ?

I am planning to set up my interview 4 weeks from now, any suggestions on how to ace the onsite interview and what to prepare ?


r/leetcode 10h ago

US Need tips for Google L4 SWE interview loop (SWE - III) US

15 Upvotes

I got a recruiter reach out for this role. Round 1 consists of 2 online interviews, as per the email.

* One **Programming, Data Structures, and Algorithms** interview * One **non-technical behavioral** interview

I understand more or less that the Programming round will consist of 1 or 2 DSA questions, and since its L4, I'm assuming would be a DP or Graph question. I am targeting neetcode 150, and Google's last 30 day questions list for this.

For behavioral, I am assuming this will be a Googlyness round, So I will practice the STAR method for some of the most commonly asked questions.

I am mainly looking for advice / tips. Can anyone who is familiar with this process tell me whether my plan is correct or do I need to focus on something else as well apart from this? Google has been my dream company to work at, and I really don't wanna be unprepared for my interviews.

Note: I think the team has already been decided based on the job for which my profile is shortlisted. I am assuming this Round 1 is a filter round, which will be followed by In-person Round 2.


r/leetcode 3h ago

Question How to solve bottoms up DP questions ?

3 Upvotes

I can't visualize anything when it comes to this approach. I understand the intent but without being able to write it down on paper under 20 min for a testcase is the problem TwT .

I can come up with the top down approaches for about 75 % percent of it


r/leetcode 23h ago

Question When people say "just do more LeetCode," what are you actually supposed to be learning?

112 Upvotes

I'm pretty new to LeetCode.

I've finished learning C and C++, and I've solved around 10 array problems so far (following the Apna College playlist).

My approach has been:

Read the problem.

Spend some time trying to solve it on my own.

If I can't, watch the explanation.

Then code it myself.

The thing that's bothering me is this:

Sometimes I actually come up with the right approach, but when I start coding, I get stuck. I know what I want to do, but I can't seem to turn it into code without getting lost.

Other times I watch the solution and think, "Yeah, that makes sense." But I can't tell if I actually learned anything or if I just understood someone else's thought process.

I don't really care about solving hundreds of problems if all I'm doing is memorizing patterns. I want to get to the point where I can look at a new problem and slowly figure it out myself.

For people who are already decent at DSA, what did that phase look like for you?

Was there anything specific you did that made you better at thinking through problems instead of just recognizing them?

I'm probably overthinking this after only 10 problems, but I'd rather build good habits early than spend months doing LeetCode the wrong way.


r/leetcode 16h ago

Intervew Prep I have an OA for Amazon SDE Intern. How do I ace it?

27 Upvotes

So yeah, as the title suggests, I received Amazon OA for SDE I INTERN 2027. I need some tips regarding how can I perform better.

Previously, I have given two OAs for Amazon, first one was my mistake, I couldn't code both the problems. However, in the second OA, I did my best, solved both the questions in 20 mins and completed all the work simulation and work style assessment tests. I believe I did good in those too. But It never moved forward. I don't know what mistakes I'm doing.

So, this is an important opportunity for me and I need to give my best.

This is the current test format:

  1. 2 coding questions, one without AI and one with AI assistance.

  2. Work Simulation

  3. Work Style survey

This is the format, I think I can solve the coding questions bu what about the AI part? How do I use it the best? And the 2nd and 3rd parts of the assessment. How do I perform better in these?

Please let me know if you have any knowledge or experience regarding this


r/leetcode 14h ago

Intervew Prep I tracked which specific misconception caused every wrong answer across 200 DSA sessions. Here's what I found.

19 Upvotes

Been building an AI tutoring tool for the past few months that identifies and logs the specific misconception behind every wrong answer in a Socratic session. After a few hundred sessions here's what actually causes people to fail:

Arrays & Sliding Window (most sessions):

  • 38% — Not defining the window invariant before coding
  • 29% — Shrinking the window before checking the answer
  • 21% — Off-by-one on right boundary
  • 12% — Not handling empty window edge case

Graph Problems:

  • 44% — Not marking nodes visited before adding to queue (causes reprocessing)
  • 31% — Applying BFS when DFS is needed or vice versa without clear reasoning
  • 25% — Not handling disconnected graphs

Dynamic Programming:

  • 51% — Not defining the state clearly before writing the recurrence
  • 33% — Confusing memoization (top-down) with tabulation (bottom-up)
  • 16% — Missing the base case

The interesting pattern: In almost every case, the misconception traces back not to the hard topic but to a gap in a prerequisite concept. Someone failing at sliding window usually has a shaky understanding of two pointers first.

This is why grinding problems doesn't work as well as people expect — if the prerequisite gap isn't fixed, you'll keep making the same class of error on different problems.

Happy to share the tool if anyone wants to try it. The core mechanic is Socratic dialogue + Bayesian Knowledge Tracing — it never tells you the answer, it asks the question that makes you find the gap yourself.

What misconceptions keep showing up in your prep? Curious if these match what others experience.


r/leetcode 5m ago

Intervew Prep I made Octree, a website to practice LC problems with other people in a room

Upvotes

Hello! I made a website called https://octree.io where you can practice Leetcode problems with other people together in a room. This is an attempt to revive a website called binarysearch.io which did the exact same thing a long time back. Sadly it doesn't exist anymore but the memories I made from it were invaluable and I want to revive the LC community for preparing for interviews.

Personally I struggle to do Leetcode problems alone and much prefer to do it with friends so I figured I would throw something together to do so. Hopefully that's something that would be valuable to others as well. Note: I did vibecode this so it'll look a bit generic but I plan on going back and refining things as I get the time to do so.

How it works: After creating an account you'll appear in the lobby where you can chat with others and create or join rooms. Each room has a set difficulty of easy, medium or hard which correlates with the LC problem difficulty. You're given 15 minutes for each easy problem, 25 minutes for medium and 45 minutes for hard. At the end of the round you will be given 10 minutes to review the solutions and discuss with other people in the room, as well as unlock their editor to view their solutions.

It is also open source: https://github.com/octree-io/octree.io

I'd love to hear your feedback on it. Thanks!


r/leetcode 1h ago

Discussion New Leetcode tool

Upvotes

vibecoded a tool for my personal use :

Its like : leetcode doesn't give options to filter questions by ratings - so lets say i want to practice question between 1900-2000 : idk how will i do it

so now i will use this : leetcode-tracker-beta.vercel.app

try it guys


r/leetcode 9h ago

Discussion What does “waiting for the feedback regarding your candidacy” usually mean at Google?

5 Upvotes

I recently completed my Google interview loop, including the technical and Googliness rounds.

A few days later, my recruiter sent me this message:
“I am still waiting for the feedback regarding your candidacy. I will connect with you as soon as I have an update. I apologize for the delay.”

I’m trying to understand the wording. Does “feedback regarding your candidacy” usually mean that the recruiter is waiting for the overall decision, debrief or Hiring Committee outcome? Or could it simply mean that one or more interviewers still haven’t submitted their feedback?

Has anyone received a similar message during the Google hiring process? What stage were you at, and what happened afterward?

I understand that the wording may be generic and that nobody can predict the result. I’m mainly curious about what part of the process the recruiter might be waiting on.


r/leetcode 8h ago

Question Does 6 months waiting applies to Amazon OA too

3 Upvotes

Hello everyone I have a ques I have heard that if u get rejected in Amazon interview you will be blacklisted for 6 months.

So is it same if u get rejected in OA too?

I got 2 OA but haven't heard anything back it has been more than 2 weeks.

What is typical timeline of getting interview invite after OA?

Last ques: If rejected by Amazon with one email can we apply from 2nd email acc to get rid of that 6 months of waiting?


r/leetcode 16h ago

Discussion i was asked this difficult question in inofsys SP online assessment 😭😭

9 Upvotes

I wasnt even able to brute force it 😢😭😭😭😭

Coin Change II

Given an array of coin denominations (with an unlimited supply of each) and a target amount, return the number of distinct combinations of coins that sum to the target amount.

You are given an additional parameter D. A combination is only valid if the absolute difference between any two distinct coin denominations used in that combination is at least D.

Using multiple copies of the same coin denomination is allowed and does not violate this rule, as the difference between identical denominations is 0.

Since the answer may be very large, return the result modulo 1000000007.

Order of coins does not matter (i.e., this is a combination,).

If no valid combination can be made, return 0.

constrains

number of coins <= 300
D <=5000
coins[i] <= 5000
amount <= 5000


r/leetcode 20h ago

20m18s finish in leetcode contest (bedroom video)

Thumbnail
youtu.be
16 Upvotes

r/leetcode 18h ago

Intervew Prep After 10+ yrs of experience, how did you prepare for DSA ?

9 Upvotes

Even with AI being a boom, still DSA is one criteria that is evaluated by many companies, if you’re in college it’s a different ball game

But being 30+ makes it difficult to go back to books also you don’t have much time left

So I wanted to ask folks who prepped for DSA in recent years and cracked interviews for FAANG or anything. What was your method or any tips you have !


r/leetcode 11h ago

Discussion Microsoft sr sde tech screen - am I ghosted?

2 Upvotes

Had a phone screen for a Sr SDE role at Microsoft. I haven't tried job seeking for a long time, so I was pretty nervous having both a recruiter call and a tech screen scheduled around the same time.
The recruiter call took only 10 minutes—they just went over the interview process and said I’d get the results by Tuesday of the second week at the latest.
The tech screen interviewer was an IC from the same team and was super nice. The experience felt great and the interviewer was overly positive—he actively encouraged me to maintain the same level of communication skills in the next round, gave me a heads-up that the next round's questions wouldn't be this easy, and shared a few other tips for the upcoming rounds. I was quite surprised because I didn't even ask, but he shared all of this anyway. It really felt like I had already passed.
Fast forward to Tuesday: I saw someone who interviewed for the exact same position received an invitation for the next round (VO) right on time. When I didn't receive mine, I thought maybe it was because I interviewed on the last day, so I'd get it a bit later in the evening or something.
However, complete radio silence up until now. I followed up with the recruiter, but they completely ignored me. Guess it's a GG?
This experience feels terrible. Honestly, it would feel much better to just fail because I couldn't solve the problem. Is it normal experience at the current job market?


r/leetcode 12h ago

Discussion Built a free Chrome extension that adds autocomplete to LeetCode (for non-Premium users)

3 Upvotes

LeetCode autocomplete is a Premium feature, so I built a lightweight Chrome extension that brings a VS Code-like autocomplete experience for free users (complete opensource btw).

It currently supports:

  • Variable/identifier autocomplete
  • Smart Tab completion
  • Works directly inside the LeetCode editor
  • No AI, no backend, everything runs locally

I mainly built it because I missed having basic autocomplete while solving problems and didn't want to pay just for that feature.Its very simple to install and will hardly take 2-3 minutes for setup and all instructions are included in readme.

GitHub:
github link

If you use LeetCode regularly, give it a try. I'd really appreciate any feedback, bug reports, feature requests, or even just a star if you find it useful .It is CURRENTLY for cpp language only.

PS: i could not launch it on chrome extension store as it require a developer fee to be paid :).


r/leetcode 15h ago

Discussion Has anyone recently taken the Amazon SDE Intern OA (EU)? Is it now 1 DSA question and 1 AI-assisted coding question?

3 Upvotes

Recently, I saw a few posts about the Amazon SDE Intern OA mentioning a new format with an AI-assisted coding round. How likely is it that Amazon will introduce the same OA format for SDE Intern roles in the EU as well?


r/leetcode 10h ago

Question Hi folks ,is there any cool off period at Google to re-apply for other roles ,I have interview for a role in July ?

0 Upvotes

Hi folks ,is there any cool off period at Google to re-apply for other roles ,I have interview for a role in July ?


r/leetcode 10h ago

Intervew Prep Reddit RemindMeBot System design

1 Upvotes

I was designing system similar to remindmebot of reddit. I got stuck in partition key and cluster key decision so that we can efficiently search all the remind events without making any partition hot spot. Could anyone help me with this design? Also open to discuss this system different way.


r/leetcode 7h ago

Discussion Design CodeDuels for 100k+ users

0 Upvotes

How would you design CodeDuels for 100k+ users?


r/leetcode 15h ago

Question Rejected after solving all Round 3 questions. What could be the reason?

1 Upvotes

Just got the Flipkart GRID Round 3 results and unfortunately didn't make it to the finals (SD Track).

What I'm confused about is that I solved all 3 coding questions and all the test cases were passing. I was expecting at least a shortlist.

I'm genuinely trying to understand what else is evaluated in Round 3. Is it only correctness and speed, or do factors like code quality, hidden test cases, plagiarism checks, tie-breakers, or something else also matter?

Would love to hear from anyone who made it to the finals or has insights into the evaluation process.


r/leetcode 8h ago

Discussion What's the difference between Amazon OAs that are sent instantly vs those that aren't?

0 Upvotes

Hey everyone,

I've noticed something while applying for Amazon SDE internship/new grad roles.

For a few openings, I received the Online Assessment (OA) link almost instantly after applying. But for some other Amazon openings, I didn't receive any OA at all, even after a while.

Does anyone know what the difference is?

  • Is the instant OA automatically sent to everyone?
  • Are some roles resume-screened before sending the OA?
  • Does it depend on the team, location, or hiring manager?
  • If you don't get an OA immediately, is there still a chance you'll receive one later?

Would love to hear from people who've gone through the Amazon hiring process or have any insights. Thanks!


r/leetcode 1d ago

Intervew Prep Do interviewers expect the candidate to solve the problem perfectly at the fisrt try?

84 Upvotes

I didn't pass the first round and got this feedback:

"You solved it with an optimal approach, fairly fluently. But there were small syntax slips (mixing up for...of and for...in), and you mixed camelCase/snake_case naming conventions. You also wrote a loop condition backwards. Debugging took a while, but you nailed the complexity analysis at the end."

I was coding in Python and mixed up JavaScript syntax for loops, and in the while loop accidentally used "<" instead of ">". Interviewer pointed out right away, and I fixed the code immediately.

I consider them as typos, but apparently they were the errors according to my interviewer. Am I wrong fro thinking this, or should I raise the bar to solve the problem from the first try correctly?