r/leetcode • • Jun 27 '26

Mod Post [mod] Changes with r/leetcode.

74 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 Gold Blast Bravo Popcorn Regret

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

4.7k 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 • • 1h ago

Discussion Struggling a lot to really solidify concepts in my mind and remember things. Advice wanted.

3 Upvotes

Currently I am seeking a new job due to being laid off and a lot of the interviews I have I am gated by my lack of leetcode proficiency. I can sometimes understand the high level solutions but I always have trouble implementing them perfectly and am always missing something that handles an important edge case or optimizes the solution. As a result my initial solution always breaks. Each time I do a new problem I rarely ever solve it without looking at the solution eventually. Has anyone else been in this situation? And if so how did you get better? Doing 1-2 problems a day and trying to understand the solutions but its frying my brain.


r/leetcode • • 16h ago

Intervew Prep The interviewer can only grade what you say out loud

48 Upvotes

First 5 min: repeat the problem back, ask about input size and edge cases.
Say the brute force and its complexity before optimising, even if you know the trick.
Before coding, say the plan in two lines.
While coding, narrate decisions, not keystrokes.
Before saying "done", walk one example through your code.

Practising this alone feels silly. Recording yourself or doing it with one friend fixes that fast. What habit helped you most?


r/leetcode • • 15h ago

Question Which courses actually helped you get a job at Google/FAANG? Looking for a structured roadmap with placement support

21 Upvotes

Hi everyone!

I'm a Lead Software Engineer with around 9 years of experience in .NET, React, and full-stack development. I'm looking to transition into Google or another FAANG company, ideally into an AI Engineer / AI Architect / Software Engineer role.Im naive at DSA and design.

I'm willing to invest in a good course or structured programme, but I don't want to spend money on courses that just sell dreams of high packages.

I'd love recommendations from people who have actually cracked Google, Microsoft, Amazon, or similar companies.

A few questions:

Which courses or programmes genuinely helped you crack FAANG interviews?

Is Educative, Udemy, Interview Kickstart, Scaler, or any other programme worth the investment?

Are there programmes with genuine placement assistance or referrals?

For someone with 9 years of experience, what should I focus on: DSA, System Design, LLD, AI Engineering, or something else?

Did any course directly contribute to getting your offer, or were free resources sufficient?

I'd especially appreciate advice from people who have personally received FAANG offers, rather than course promoters.

Thanks in advance! 🙏


r/leetcode • • 19h ago

Intervew Prep Best system design course for FAANG interviews at 2+ years?

25 Upvotes

Which course would you recommend for learning system design thoroughly and preparing for FAANG interviews targeting 2+ years of experience? Would love to hear what worked for you.


r/leetcode • • 6h ago

Intervew Prep Amazon Leo (WA) – L5 Embedded Software Engineer Final Loop: Interview Structure and Questions Asked?

2 Upvotes

Hi everyone,

Has anyone recently completed the final interview loop for an L5 Embedded Software Engineer role at Amazon Leo?

I'm preparing for my final loop and would really appreciate hearing about your experiences.

I'm particularly interested in:

  1. Interview structure: Is it 3 coding rounds and 1 system design round, or is the structure different?

  2. Exact coding questions: What specific coding problems were you asked? Were they LeetCode-style DSA or more embedded C/C++ focused?

  3. System design: What exact system design problem or scenario were you asked to solve? Was it high-level system design or embedded/low-level design?

  4. Embedded technical questions: What specific questions came up around RTOS, concurrency, memory management, interrupts, device drivers, or debugging?

  5. Leadership Principles: Which LP questions were asked, and how were they distributed across the rounds?

If you remember the exact questions or even similar examples, that would be extremely helpful for preparation.

I'm especially interested in recent L5 Amazon Leo/Kuiper interview experiences rather than general Amazon SDE interviews.

Thanks in advance for any insights!


r/leetcode • • 6h ago

Intervew Prep 2027 Bloomberg system design asked quesions?

2 Upvotes

Any one who have been through Bloomberg system design interview for 2027 round, can u share me the question that u have been asked?


r/leetcode • • 1d ago

Intervew Prep Best system design course for FAANG interviews at 5+ years?

207 Upvotes

Which course would you recommend for learning system design thoroughly and preparing for FAANG interviews targeting 5+ years of experience? Would love to hear what worked for you


r/leetcode • • 3h ago

Intervew Prep Day 29: knocked out 7 foundational array problems & noticing real progress

1 Upvotes

Hey everyone,

I finished Day 29 today. Even with Chhath Puja festivities keeping me busy and tired, I sat down and cleared seven foundational array problems in a quick session.

Looking back at when I first started, even basic array manipulation used to trip me up. Today, the core patterns clicked right away, allowing me to breeze through the standard logic and focus on clean implementation:

  1. Left Rotate an Array by One Place: Saved the first element, shifted elements left in a single pass, and placed the saved element at the end.

  2. Left Rotate an Array by D Places: Applied the three-step reversal algorithm to rotate in-place in O(n) time and O(1) space.

  3. Move Zeros to End: Used a two-pointer swap approach to shift non-zero elements forward while keeping relative order intact.

  4. Linear Search & Maximum Consecutive Ones: Practiced clean single-pass tracking and boundary resets.

  5. Find the Union of Two Sorted Arrays: Used two pointers to merge elements in sorted order while skipping duplicates.

  6. Find Missing Number in an Array: Used the expected sum formula (and XOR properties) to find the missing value in O(n) time without extra space.

I still need to circle back for a dedicated Graph revision, but seeing how much easier foundational problem-solving feels now is great motivation.

See you guys tomorrow for Day 28!


r/leetcode • • 8h ago

Intervew Prep SaaS Labs SDE-2 Interview Experience – Need Guidance

2 Upvotes

I have an upcoming interview with SaaS Labs for an SDE-2 position. I've received an email for the initial screening round scheduled for Monday. I wanted to know if anyone has recently interviewed with SaaS Labs for an SDE-2 role. It would be really helpful if you could share: How many rounds are there in the overall interview process? What kind of questions are asked in the screening round? What topics should I focus on for preparation? Are there separate DSA, machine coding, system design, and managerial rounds? How difficult is the overall interview process? Any recent interview experiences or preparation tips would be greatly appreciated. Thanks in advance!


r/leetcode • • 1d ago

Intervew Prep The constraints usually tell you the pattern before the problem does. A cheat sheet with Python-sized limits

54 Upvotes

The constraints at the bottom of a problem usually narrow down the pattern before you've finished reading the story. Reading them first is a cheap speed-up.

Rough budget: Python does about 107 simple operations per second. C++ and Java do roughly 10x more, so shift each row up if you use them.

If n is up toYou can affordUsually means
10O(n!)permutations, brute-force backtracking
20O(2n)subsets, backtracking, bitmask DP
200O(n3)interval DP, Floyd-Warshall
3,000O(n2)2-D DP, all pairs, expand around centre
105 to 106O(n log n) or O(n)sorting, heaps, hashing, two pointers, sliding window, prefix sums, monotonic stack
109 or moreO(log n) or O(sqrt n)math, binary search

One that trips people up: n is only 104 or 105, but the values go up to 109, and the question asks for the minimum or maximum X that still works ("minimum speed", "least capacity", "largest minimum distance"). That's binary search on the answer: O(n log(max value)).

Two words that override the table:

  • "Contiguous" (subarray, substring) → sliding window or prefix sums. "Subsequence" (order kept, gaps allowed) → DP or greedy, or two pointers if you only need to check whether one string is a subsequence of another.

  • "Sorted" → two pointers or binary search before anything else. Not sorted, and the original order doesn't matter for the answer? Sort it yourself first.

Wording → pattern, the ones that come up most:

  • "two numbers that add up to", "seen before", "group the" → hash map / set

  • "longest / shortest substring with", "at most k distinct" → sliding window

  • "next greater / smaller", "how many days until" → monotonic stack

  • "top k", "k closest", "running median" → heap (two heaps for the median)

  • "all combinations / subsets / permutations" → backtracking

  • "shortest path" in an unweighted grid → BFS; with weights → Dijkstra

  • "prerequisites", "can you finish all" → topological sort

  • "are these connected", "number of groups" → union-find or DFS

  • "overlapping intervals", "how many rooms" → sort by start, then sweep

  • "numbers from 1 to n", in place, O(1) extra space → cyclic sort

  • "number of ways", "minimum cost to reach" → DP

A habit that makes this stick: after every problem, write one line, "the cue was ___, so the pattern was ___". After a few weeks you start spotting the cue before you've read the whole problem.

What cues do you use that aren't on this list?

Edit: good additions from the comments:

  • "return the answer modulo 109+7" → you're counting ways, so DP or combinatorics (u/TSandwich73)

  • minimum feasible value → check the answer space is monotonic (if X works, bigger X works too), then binary search on the answer (u/UrbanFalcon_72)

  • no constraints given in the interview? Ask "how big can the input get?" (u/LebronManning)


r/leetcode • • 1d ago

Question Ai assisted Coding Interview Google L5

28 Upvotes

Howdy 👋
Has anyone recently gotten an AI assisted coding round for L5 software engineer role? Recruiter said it would be like Leetcode only but with Gemini. But Reddit says it could be debugging into a massive repo or open ended coding problem similar to system design round.

Please share your experience. I will post mine once my round is complete to help out the community and fellow dreamers. Thanks!


r/leetcode • • 8h ago

Intervew Prep Any ex-Meta swe interns here or anyone currently in process could you please share tips that worked for you

1 Upvotes

Currently a junior CS at Non-target(T80 school) really need some advice on how to get a proc from Meta would really appreciate any tips!


r/leetcode • • 11h ago

Intervew Prep Leetcode interview study buddy

1 Upvotes

Hi
I m looking for leetcode interview study buddy
,who are doing company specific leetcode problems and are not beginners
We can discuss daily company specific problems by screen sharing or voice call


r/leetcode • • 17h ago

Discussion Whats your best revision sheet before interview ?

3 Upvotes

How to approach DSA before interviews in 1-2 month ?


r/leetcode • • 12h ago

Discussion Any update on Amazon Job ID: 10454438 ??

1 Upvotes

I applied for the Software Development Engineer I, Amazon University Talent role (Job ID: 10454438) a week ago. Has anyone received an OA link for this position yet?


r/leetcode • • 14h ago

Intervew Prep Databricks AI algorithms Interview

1 Upvotes

Hello,

I want to ask if there is sb who gave the DB interview and if it could share what the interview expected them to do? Was it talking to the AI to write the whole code, should you also build the test cases together with the AI? What seemed to be the expectations from the interviewer? Did it have more follow-ups that needed to be coded with the help of AI?


r/leetcode • • 15h ago

Intervew Prep It is only me has the feeling that the coding interviews of AI companies are quite exhausted?

1 Upvotes

Basically the AI companies' coding interviews each round question is composed of multiple parts. It is quite exhausted to answer each part with bug free. Curious how you guys navigate through the multiple parts? Thanks.


r/leetcode • • 15h ago

Question Anyone gave Wayfair oa on November first week for software intern role 2027

1 Upvotes

Gave the oa on 2 november after getting shortlisted off campus

Has anyone else given the oa and got any callback?


r/leetcode • • 1d ago

Question Looking for a Discord community focused on DSA and problem-solving

17 Upvotes

Preferably a group where people regularly discuss questions, share resources, participate in contests, and help each other improve.

Share Discord server links . Thanks!


r/leetcode • • 16h ago

Question AGS Tech Solutions Architect Early career 2027 - OA

1 Upvotes

Hi, has anyone taken the OA for this role ? Does it have leetcode questions ? My recruiter sent me a link to help me prepare for the OA and it was a link to amazons leetcode questions but I have seen people say they got no leetcode questions so I’m just wondering if she sent it by mistake or it’s a template everyone gets. If you received a OA for this role , did your recruiter include a link to leetcode practice questions in the email? Thanks a lot .


r/leetcode • • 1d ago

Intervew Prep Is it too late to start DSA and LeetCode in my final year?

27 Upvotes

I’m in my final year of CSE (AI/ML), and honestly, I’m not well prepared for placements yet. I know the basic concepts of DSA, but I haven’t done much problem-solving or LeetCode.

Is it too late for me to start seriously preparing for DSA and solving LeetCode problems?

I’m looking for some genuine advice, especially on how to actually understand the logic behind a problem and figure out which approach to use. I often find it difficult to understand how to come up with a solution, even when I know the basic concepts.

For those who have been through this, how did you improve your problem-solving skills? What would you recommend I do from here?


r/leetcode • • 18h ago

Question How do companies rate your performance in a coding interview?

1 Upvotes

Do they consider the time it took for you to complete each problem? Do you give partial credits for passing some of the test cases?


r/leetcode • • 1d ago

Question Intuit OA - Full Stack SWE Intern

7 Upvotes

Has anyone completed the OA for this? Is it auto and what to expect in terms of the difficulty?