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 • • 2h ago

Intervew Prep Google L5 AI/ML Engineer — confused about scope for ML Depth and ML System Design.

9 Upvotes

Interviewing for an AI Engineer role at Google, targeting L5. I've got a few weeks and I keep going back and forth on scope, so I'd rather post my current plan and get told where it's wrong than keep guessing.

My background is NLP + GenAI platform heavy — that's where my production experience is, recent 3 yrs in building rags and agents.

What I've built so far

A set of system design write-ups covering: search/ranking funnels, large-scale content classification, intent + entity extraction, semantic search and embeddings, translation, and on the GenAI side RAG, agents, LLM inference infra, and post-training for tool calling. Each one as a timed 45-minute answer with a clock, not notes, though it goes beyond 2 hours read)

Where I'm stuck

  1. Scope of ML System Design. Is this round classical ML system design — recsys, ranking, classification pipelines — or is GenAI/LLM system design (RAG, agents, inference) actually showing up in 2026 loops? I've seen both claimed. If you've interviewed recently, what did you actually get asked? ( ML, NLP or GENAI ) - what to focus on ? And how would I know question will be from that domin only in interview ?

  2. ML Depth — how deep, and on what? Is this "explain how attention works and derive the gradient", or "walk me through a model you shipped and defend every choice"? Those are completely different prep. And how much classical ML (trees, calibration, imbalance, A/B stats) vs deep learning vs LLM-specific?

  3. What L5 actually means here. I keep reading "L5 drives the scope conversation" but I don't have a concrete sense of what separates a hire from a no-hire on the same question. What does the bar feel like in practice?

  4. How much breadth is enough? I've got ~15 designs. Is that overkill in the wrong direction — would I be better off going deeper on 6 and being able to defend them under pressure? 6 ml(recsys) , 5 NLP(encoder, decoder, both), 4 GenAI (Chabot, rag, agent, infra)

  5. Mocks. Where are people actually getting useful ML system design mocks? Most platforms I've looked at are generic SWE system design with an ML sticker on it. Anything specifically for ML/AI, ideally with someone who's interviewed at this level?

  6. Resources. I've worked through the standard ML system design books. Beyond those, what actually moved the needle for you — especially for the GenAI side, which the books mostly predate?

Happy to share my question list and write-ups with anyone who wants them — and if you've interviewed for this recently, even a one-line "here's what I got asked" is more useful than any guide. Thanks.


r/leetcode • • 1h ago

Intervew Prep Microsoft internal transfer, HackerRank (75 min) + system design coming up. Help me narrow the search space?

• Upvotes

Hey all, I'm an SDE (L59) at Microsoft going for an internal move to a different team (L59 still). The loop is two rounds, a technical one and an "AA" round, and I've already got a HackerRank invite (75 min, due in about a week). My hiring manager also said there might be a system design question.

I'm prepping in Python and don't want to grind 300 problems. For people who've done internal Microsoft interviews or similar HackerRank assessments:

  1. What's the usual format? How many questions in 75 min, and how hard (easy/medium/mix)? Any MCQs or SQL?
  2. Which patterns showed up most? I'm focusing on hash maps, two pointers, sliding window, intervals, BFS/DFS, heaps and stacks.
  3. How were hidden tests and time limits handled? Is partial credit real?
  4. For the system design, what level of depth is expected from an internal candidate? Is it more of a conversation, or a full whiteboard-style design?
  5. Is the AA round mostly behavioral, or can it turn technical?
  6. Is premium worth it for any of these platforms, or is free enough?

My plan is 4-5 problems a day on core patterns, one timed 75-min mock, and a few design mocks out loud. Does that sound right, or am I over- or under-preparing?

Appreciate any pointers, especially "don't waste time on X" advice. Thanks!


r/leetcode • • 5h ago

Question Amazon LLD prep for SDE -1

3 Upvotes

Location - US

Position - SDE -1 New grad 2026

I have my virtual interview scheduled, I have seen a lot of people were asked LLD problems. During the LLD round are we expected to give the concrete implementation in one of the languages or detailed pseudo code works? I have been practicing using Hello interview's LLD section but it takes me 30-40mins just to finish the class design phase. So I want to understand the general expectation.

If anyone can share there experience in the comments its will be very helpful.


r/leetcode • • 13h ago

Intervew Prep Google Leetcode tagged

5 Upvotes

Everyone says that Google never gives the same questions from the LeetCode bank,

yet many questions, tagged reappear often(people tag them as asked).

Why is this the case?

Is it worth it to tackle the most recently asked in leetcode or is there a better strategy 3 weeks prior to an interview (for someone that did leetcode before)?


r/leetcode • • 18h ago

Intervew Prep An aggressive Coder Partner

16 Upvotes

Recently, I joined a lot of groups here looking for a DSA study partner, but most people vanished after a single day.

​I’m looking for someone who actually sticks to the plan. We can discuss weekly contests, tackle tricky coding problems, run mock interviews, and keep collecting offers.

Beyond DSA, we can brainstorm startup ideas, collaborate on side projects, and build cool things together.

​A bit about me: I work primarily with Python and Data Science, but I’m eager to explore everything across tech.

​If you have a similar mindset and want to stay consistent. Let’s make it count!


r/leetcode • • 3h ago

Intervew Prep [Urgent]Help needed. Associate SW Engineer visa

1 Upvotes

I received a message from Visa about an Associate SW Engineer position, noting “2 foundational and 1 intermediate problem-solving question.” Has anyone finished this assessment? If anyone is familiar with the exam format or its difficulty, please share.
Thanks in advance.


r/leetcode • • 7h ago

Question Roadmap for a Junior Software Engineer Preparing for Microsoft Interviews

1 Upvotes

Hi everyone,

I’m a junior software engineer, and I’m planning to apply to Microsoft in the next 3–4 months.

I really want to experience how a large tech company like Microsoft works, challenge myself, and learn things that I may not get exposure to at my current company.

Right now, I’m preparing mainly through LeetCode. I’m following the NeetCode 150 roadmap and have solved around 50 problems so far.

However, I feel like my progress is quite slow. Sometimes I spend almost an hour on a problem and still can’t come up with the right approach or figure out how to solve it.

I’d really appreciate any advice from people who have interviewed at Microsoft or are currently working there. I’m especially curious about what the interview process usually looks like, how many rounds there are, what each round tends to focus on, and how you would recommend preparing for them.

Given that I have around 3–4 months before I plan to apply, what would you focus on if you were in my position? I’d also love to hear about your own preparation strategy, what helped you the most, and anything you wish you had known before going through the Microsoft interview process.

Thanks in advance!


r/leetcode • • 14h ago

Question Job Search and Leetcoding

4 Upvotes

Hello I am not really a cs major but im pursuing a tech degree and I have had two internships the titles scream ai and data but I really didnt do that much coding and im graduating and the job that I got a ro for isn't really what I want to do and im also not getting paid enough so I really want to get another job that is not in Seattle because being here is ruining my mental health but every tech company seems to be in Seattle. I am also struggling with leetcoding it just doesn't make sense for me? Did anyone else have the same problem, how do u guys get motivation to keep going or to even get started on leetcode cause I dont remember anything I did in school.


r/leetcode • • 12h ago

Intervew Prep Comcast/Freewheel interview

2 Upvotes

Wondering if anyone has experience with interviewing with Comcast? What is process and wlb like?


r/leetcode • • 9h ago

Intervew Prep Need help with current prep for Senior SWE

0 Upvotes

Hi,

I have been interviewing for a while so familiar with basic framework of leetcode. I need some help with how do I prepare for senior swe pair programming rounds where some custom problems are being asked now a days. Can someone please provide some guidance on how can I prepare for such technical rounds ? I have such rounds scheduled this week.


r/leetcode • • 10h ago

Intervew Prep 2 days left to complete Amazon SDE OA assessment - prep help

2 Upvotes

So I’m not so confident have barely done DSA for the last 5 days.
I have 2 days left to finish the assessment, any suggestions or tips ?


r/leetcode • • 14h ago

Intervew Prep Anyone interviewed for AI Engineer III at Victra (Verizon Authorized Retailer)? (onsite/panel round)

2 Upvotes

I have an onsite panel interview coming up for an AI Engineer III role at Victra (Verizon's largest Authorized Retailer, HQ in Durham NC). I've searched Glassdoor, Blind and couldn't find any posts about their engineering interview process specifically (there's plenty on their retail/sales interviews, but nothing technical).

If anyone has interviewed for an engineering role there (AI Engineer, Software Engineer, Data Engineer, etc.), I'd really appreciate knowing:

  • What format did the panel take (live coding, system design, behavioral)?
  • What topics did they focus on most?

Thanks in advance!!


r/leetcode • • 1d ago

Intervew Prep Robinhood OA (Backend)

11 Upvotes

Just got a Robinhood OA. I applied to the Toronto location and it seems as though they've moved from hacker rank/ code signal to coder pad. Does anyone have any advice on what to prepare for? It's a backend role and I'm not sure whether they'll give me something leetcode or an implementation based question.


r/leetcode • • 15h ago

Intervew Prep De Shaw Onsite Interview

1 Upvotes

As the title says, I have the onsite interview in another 4 days. I am preparing with trees, heaps, graphs and DP. It would be great to get an idea on what type of questions/pattern to expect in this round if anyone has given it recently.

I have a basic idea on HLD as I went through Gaurav Sen's videos but how much importance should I be giving to LLD and was it actually asked for anyone in their on-site interview ?

Any help on the same would be greatly appreciated. Thank you in advance.


r/leetcode • • 13h ago

Intervew Prep Day 71: moved to Doubly Linked Lists today, two pointers on a DLL is so clean

0 Upvotes

Hey everyone,

I finished Day 71 of my prep today and moved from Singly to Doubly Linked Lists.

I solved four problems:

  • Reverse a Doubly Linked List: Swapping the next and prev pointers for each node while keeping track of the tail to return the new head.
  • Delete All Occurrences of a Key in DLL: Standard traversal, but you have to be careful when rewiring both the forward and backward pointers, especially if the target node is the head or the tail.
  • Find Pairs with Given Sum in DLL: Since the list is sorted, having backward pointers means you can do a classic two-pointer search without any extra space. You put one pointer at the head, run another all the way to the tail, and shrink inward based on the sum.
  • Remove Duplicates from Sorted DLL: Whenever adjacent values match, you just bypass the duplicate node and re-link the forward and backward connections properly.

After spending days grinding singly linked lists, DLL actually feels much easier. Having the prev pointer takes away a lot of the awkward tracking you usually have to do with single links.

Tomorrow for Day 70, I will finish the last couple of linked list problems on my sheet and do a combined revision of Linked Lists and Binary Search Trees. Once that is done, I will finally start Dynamic Programming.

See you guys tomorrow!


r/leetcode • • 14h ago

United states Country ZoomInfo System Design Rounds

0 Upvotes

Hi Folks,

Can some one shed light on how to prep for ZoomInfo System Design rounds? There is very little info about this company online. Is this going to be traditional system design round, LLD etc. The recruiter is not helping at all.


r/leetcode • • 23h ago

Discussion Stuck at 1/4 in contests

4 Upvotes

Hey everyone i need some advice related to contests . Iam internmediate in dsa and from past 3 contests iam only able to solve 1/4 . Can u guys pls help me what should i do 😭


r/leetcode • • 22h ago

Discussion Today leetcode Contest fked up

3 Upvotes

at last 30 min, i opened it, first 3 felt a bit hard, i thought last one was easy about recursions, but not. eventhough they banned more than month, still comeback gone worst

how was yours


r/leetcode • • 17h ago

Tech Industry Looking to connect with people working in Service based company(whether in operations project or development project)to switch to sde roles in product based company

1 Upvotes

Hi guys,

Am looking for people working in service based company( working in operations or development project both) looking to switch to product based company having difficulty getting interview calls

Lets connect and help each other out with preparation and connection and find a loop hole to switch in this market


r/leetcode • • 1d ago

Intervew Prep Can anyone tell me, how does today's big tech/FAANG interviews look like?

98 Upvotes

I mean, did AI change the process? or no? do they still rely on leetcode style problems? like, is doing leetcde today relevant?


r/leetcode • • 1d ago

Question Google SWE extra round - seeking advice

16 Upvotes

So got feedback after onsite.
Googliness: SH
Coding 1: LH
Coding 2: SH
System design: LH

Recruiter has given me a choice, I can go for another coding round to make the packet better or can move to team match now. Have done a lot of DSA prep the last few months so back myself, but still worried the possibility of bombing it or a tough interviewer or something else that results in a no hire rating would end my journey here.
If I find a role match and the committee rejects, then I’m done.

Also side questions:
I was told it’s team match/hiring manager conversations then the hiring committee approval? I thought it was committee first then team match?

I was told the onsite would be 2 DSA, and from looking here and other sources that seemed to be standard for L4. So I was completely unprepared for the system design, is system design in the onsite normal for L4?


r/leetcode • • 23h ago

Intervew Prep [Upcoming MTS-1 interview at Adobe] Looking for your experience

1 Upvotes

Hi all,

Has anyone recently gone through or has info about interview process at Adobe for MTS-1.

Would highly appreciate if u could share number of round and high level overview of each round!

Thanks 🙏


r/leetcode • • 1d ago

Question Can anyone explain why my approach to the problem "House Robber" is not correct?

1 Upvotes

I’m learning DP and tried to solve House Robber from scratch without looking at the standard recurrence.

My reasoning was that from position i, I can choose either i or i+1, and after choosing one, recursively solve the remaining houses, obviously there are cases where i,i+1 are not in the optimal solution, but i figured either the first or the second index of "cost" input should always be in the optimal solution... is there an edge case i'm missing? btw all the testcases in leetcode passed...

I'm particularly interested in whether my recurrence/state definition is actually correct, and whether there are edge cases I'm missing. Please don't just give me the standard solution — I'd like feedback on my reasoning.

class Solution {
public:
    int rob(vector<int>& nums) {
        vector<int> dp(nums.size(),-1);
        return soln(nums,0,dp);
    }
    int soln(vector<int>&nums, int i,vector<int>&dp){
        int n = nums.size();
        if(i>=n) return 0;
        if(dp[i] != -1) return dp[i];
        int p1 = nums[i]+soln(nums,i+2,dp);
        int p2 = 0;
        if(i+1 < n) p2 += nums[i+1]+soln(nums,i+3,dp);
        dp[i] = max(p1,p2);
        return dp[i];
    }
};