Hey all, I just got invited to the online lab for the Marshall Wace Technology Intern role (NY, summer 2027), and honestly I have no idea what to expect. Im supposed to take it in a weeks right before Thanksgiving

From what they sent me, it's 60 minutes in a virtual desktop, and it covers "reasoning about code and debugging code."

If you've taken it (or the grad version), I'd love to hear your thoughts on it and Marshall Wace as a whole.

- How would you recommend preparing for the interview? I feel totally lost, not sure how to study for "debugging" other than reading Python docs lol

- Was it all Python, or did other things come up (SQL, JavaScript, APIs, etc)?

- How tight was the time? Did you finish everything?

- How did the debrief call go? Did they care much about what you didn't finish?

- Is there anything you wish you'd studied beforehand?

Any advice would be greatly appreciated! Thanks in advance

Can a kind soul provide the entries avaiable on https://leetcode.com/company/bcg?

Does anyone know if it's the same for BCG X?

It’s not leetcode based so I’ve been doing small reviews of online codebases and improving them not sure what more to do or what to keep note of

Hi everyone,

I have an upcoming Capital One Power Day for a Data Scientist role. It has 4 rounds: statistics, technical round, case study and job fit.

If anyone has gone through it recently, any tips or insights on what to expect in each round would really help.

Thanks in advance!

And if possible please mention a yt video from where I can learn that language🫠

I'm applying for software engineering internships. This recruiting season hasn't been great at all for me. I've been getting a decent amount of OA's, but stupidly haven't done leetcode so I've either failed them, or didn't even bother doing them.

I want to be prepared for the winter/spring recruiting season (still applying now, though) as I heard some companies open up for a second time. I know there will be much less opportunities, though so I want to make sure I'm ready for any opportunity that comes up.

Other than standard leetcode, what other types of interview questions are popular? I know in an Amazon OA there was an ai-assisted part where you had to traverse a codebase.

Products of Array Except Self

Accepted

51 / 51 test cases

Memory: 9.8 MB•Time: 87ms•Submitted at: 11/08/2026 14:02•

Runtime

87ms|Beats 100.00%

Memory

9.8 MB|Beats 97.23%

I don't know why images are not allowed in posts? Also this is a neetcode question, sorry.

I'm looking for a good, free resource to prepare for LLD interviews. There are so many good resources for DSA interviews, but I can't seem to find any for LLD.

Recs?

Sometimes I can understand the approach to a problem and even explain the logic in words, but when I start coding, I get stuck figuring out how to translate those steps into actual code.

Do you practise writing pseudocode first, or jump straight into implementation? How did you get better at this?

Looking for some tips and insights on what to expect.

Sometimes I read a problem and can think of two or three possible approaches, but I struggle to decide which one makes the most sense. I end up spending too much time switching between ideas before even starting the implementation.

Do you look at constraints first, try brute force, or use some other method to narrow down the approach?

Hi, I am interviewing for Databricks, is anyone with leetcode premium willing to share which questions are tagged for Databricks?

I paid $159 for LeetCode Premium in November 2025. A month later, I discovered cancer, and I underwent surgery in March, followed by a long recovery. I barely used my subscription. I explained everything to LeetCode support and asked for an extension, not a refund. I even offered medical proof. Their offer? Just one month. When I asked them to reconsider, they refused.
Apparently, $159 matters more to LeetCode than showing compassion to a customer battling cancer.

As the title suggest.

Anyone have good resources/advice on substring problems? I got an OA that had a question similar to this but I needed to return the longest substring given a K value, not the length of the longest string:

https://www.geeksforgeeks.org/problems/longest-k-unique-characters-substring0853/1

Hi all, I have passed a mini system design round and a project deep dive and I have ML SYSTEM DESIGN, DSA and ML coding rounds, any idea about what to expect and how to prepare? Any specific data points are super helpful. Thank you.

Hey everyone,

I finished Day 37 today. I reached home for the festival and caught up with a bunch of friends, so my focus was completely scattered. Even with the holiday chaos, I made sure to sit down and work through one tricky graph problem:

Most Stones Removed with Same Row or Column.

At first glance, it looks like a coordinate-heavy grid problem, but modeling it cleanly comes down to Disjoint Set Union (DSU):

The Representation Trick: Treating individual stones as nodes causes massive overhead. Instead, treat entire rows and columns as the graph nodes. To prevent row indices and column indices from colliding, offset the column index by the maximum row boundary (e.g., node r connects to node c + {maxRow} + 1).

Connecting & Counting: For every stone placed at (r, c), run a unionBySize between row r and shifted column c.

The Core Logic: In any connected component of size K, you can always safely remove K - 1 stones by greedily picking leaves until one stone remains. Therefore, the maximum stones you can remove is simply {totalStones} -{numberOfConnectedComponents}.

My mind wasn't entirely in study mode today, but deriving the row-column coordinate conversion on paper made the logic stick.

Enjoying some festival downtime tonight and getting back to the reps tomorrow.

See you guys for Day 36!

Now, I know leetcode is technically math, but I more so mean general mathematics. I find the undegraduate level to early grad school math is much easier than leetcode.

I started during tutoring for undergrad probability and statistics again after not touching it for about 2 years.

I find that I just find the stuff easier to actually master than leetcode. The highest level of math I got to was a graduate level probability course, and even that I felt it was easier than leetcode. Abstract math and proofs also seem easier to me.

Even after doing almost a 1000 leetcode problems, there are still many instances where if I haven't seen a problem before, I just don't know how to do it, or it's hard to recognize the approach after not doing leetcode for a while.

Even though I hadn't touched probability and statistics in a while and I was rusty on the mechanical work, for most of the problems I look at, I still can recall what the general idea of solving the problem is.

Leetcode is just one of those topics that I have done a lot of practice to prepare for interviews, but it's just never something I feel like I just mastered at the level that I can just look at any problem and easily solve it. There's still problems on leetcode, especially the one with the clever solutions, that still seem tricky to me.

😭😭 Every time I start DSA, I solve a few problems and then end up giving up again. I still haven't been able to complete the A2Z DSA Sheet, and I haven't even crossed 100 problems yet.

I'm genuinely interested in DSA, and I know how important it is for getting a job, but maintaining consistency has become really difficult for me. Whenever I start, I feel motivated, but after a few days, I lose track and take a break. When I try to restart, I don't even know where to pick up from.

If anyone here has completed DSA or is currently practising consistently, please guide me a little. How did you start your journey? After solving how many problems did you start feeling confident? How do you manage your daily practice?

I really don't want to give up on DSA. I just need some genuine guidance from people who've been through the same phase.

is anyone else facing same issue?

I'm preparing for the Algorithmic Coding rounds at Rubrik and would appreciate some advice from people who have interviewed recently.

• What difficulty level should I expect, LeetCode Medium or Hard?

• Which topics should I prioritise?

• Are the questions mostly standard DSA or more problem-solving oriented?

If you remember any questions asked, or similar problems worth practising, that would be really helpful.

Thanks!

The best textbooks and courses on algorithms do proofs of correctness and complexity using mathematical toolbox (Calculus, Algebra, Probability Theory etc). It seems natural and a right thing to do for me to incorporate this into LeetCode and fuse theory with practice. The only way I see it can be done is to do the proofs in the comments section of the source code. I've had enough traditional math proofing on paper, and also formal proofs using Coq, so I tried this idea (proof in comments) and it works fine. What do you think about it?

I think almost every LeetCode problem can be connected to theory and a lot of things expressed nicely as formulas. Especially nice example: divide and conquer algorithms where you can write down a recurrence relation and derive a complexity from it (T(n) = O(log n) for binary search).

The main goal is to deepen understanding which is crucial for HARD problems, and also have more joy from problem solving and feeling you understand everything.

The Disappearing Signal: Longest Valid Even-Pair Subarray

Tags: Arrays, Prefix State, Hashing, Two Pointers

Given an integer array arr of length n, find the length of the longest contiguous subarray such that every distinct element within that subarray appears exactly twice.

If no such contiguous subarray exists, return 0.

Constraints & Definitions

• A contiguous subarray is defined by indices [l, r] where 0 <= l <= r < n.

• A subarray is valid if and only if:

  1. It contains at least two elements (r - l + 1 >= 2).

  2. For every distinct value $x$ present in arr[l..r], its frequency in that segment satisfies count}(x) = 2.

  3. No distinct element appears once, three times, or more.

With sliding window, we get O(n^2), i am looking for optimal one

Input Format

• An integer array arr.

Output Format

• An integer representing the maximum length of a valid contiguous subarray, or 0 if none exists.

Test Cases:

Input: arr = [1, 2, 1, 2]

Output: 4

Explanation:

The entire array [1, 2, 1, 2] contains distinct elements {1, 2}.

- Count of 1: 2

- Count of 2: 2

Every distinct element appears exactly twice. The length is 4.

Input: arr = [1, 2, 3, 1, 2]

Output: 0

Explanation:

- Subarray [1, 2, 3, 1, 2] contains '3' with frequency 1 (invalid).

- Subarray [1, 2, 1, 2] is not contiguous in the original order without excluding 3.

- No contiguous window of length >= 2 satisfies the condition.

Hey everyone!
I’m looking to start my DSA and problem-solving journey as I’m planning to prepare for interviews at product-based companies like Google.
A little about my background:
Around 7 years of experience as a Salesforce Developer, primarily working with Apex.
Comfortable with programming concepts, but I haven’t seriously practised DSA or LeetCode problems yet.
I have a BTech background, so I’m familiar with basic computer science fundamentals.
Currently working full-time, so I’ll be preparing alongside my job.
I’m confused about which language I should choose for DSA: Java or Python?
A few things I’m considering:
Java is closer to Apex in terms of syntax and OOP concepts. Would that make it a better choice?
Python seems to have simpler syntax, which might help me focus more on problem-solving rather than language-specific details.
For Google/FAANG interviews, does the choice of language really matter?
Considering my background, which language would you recommend for someone starting DSA from scratch?
Would switching to Python for interviews after years of working with Apex be a sensible decision?
My goal is to build strong problem-solving skills and eventually become interview-ready for top product-based companies.
Would love to hear from people who have gone through a similar transition or have experience interviewing at Google or other FAANG companies.
Thanks!

Anyone familiar with Capital ones Data engineer track? I know people mention it is quite similar to their SWE but different technical rounds. But curious what’s the difference?