Daily (227/373 streak until LC cap)

A bit strange problem, but definitely not hard, just a bit cumbersome.

https://leetcode.com/problems/construct-product-matrix/?envType=daily-question&envId=2026-03-24

#daily #medium

Conceptual question, do you know what is "upstream" and what is "downstream" services/components in terms of dependencies or in scope of who calls whom?

Tomorrow will post the answer and explain why so.
As I typically saw a lot of confusion when 2 persons are talking about opposite things

Daily (228/373 streak until LC cap)

Today one of the easiest medium problems I have ever met in leetcode. But I'm scared of this "I", probably tomorrow we gonna have "II" and I'll be fucked

https://leetcode.com/problems/equal-sum-grid-partition-i/description/?envType=daily-question&envId=2026-03-25

#daily #medium #nopattern

Every single CEO after this AI nonsense slope collapses and their vibe coded apps start breaking apart:

Daily (229/373 streak until LC cap)

As I said yesterday, today's daily is really hard and really cumbersome, don't recommend, skip it and have a nice Thursday.

https://leetcode.com/problems/equal-sum-grid-partition-ii/description/?envType=daily-question&envId=2026-03-26

#daily #hard #nopattern

OOOOOOOOOOOOOO shit, because of oncall (btw first time oncall at snowflake, and hard nonsense problem, I actually checked the solution, understood it, explained it, but never submitted it... my streak went away, fuck)
Probably will need to use "time travel" thingy

Okay, fixed it, here we are my 3 digit number on "daily" streak

Daily (230/373 streak until LC cap)

Interesting problem, with a lot of variations, and some useful techniques to learn, references simplified version of similar problem.

https://leetcode.com/problems/matrix-similarity-after-cyclic-shifts/description/?envType=daily-question&envId=2026-03-27

#daily #easy

Daily (231/373 streak until LC cap)

Pretty hard problem, especially hard to understand, hard to build intuition and in general understand what to do. My advice would be to not proceed with that. If you want to still get use of some patterns in this problem (go to comments, I will suggest the prerequisite problem, that is common and might be helpful on the interview)

https://leetcode.com/problems/find-the-string-with-lcp/description/?envType=daily-question&envId=2026-03-28

#daily #hard #pattern

Daily (232/373 streak until LC cap)

Pretty easy, however for the first 2 minutes, initially it seemed harder than easy. However no pattern learnt

https://leetcode.com/problems/check-if-strings-can-be-made-equal-with-operations-i/?envType=daily-question&envId=2026-03-29

#daily #easy #nopattern

Daily (233/373 streak until LC cap)

The same approach as it was yesterday, free problem.

https://leetcode.com/problems/check-if-strings-can-be-made-equal-with-operations-ii/description/?envType=daily-question&envId=2026-03-30

#daily #medium

So officially, Mailchimp, the provider I was using to gather email subs from andreyka26.com - is shithole.

I wanted to test email form and tried to test send it to myself, they immediately marked it as malicious, however it was their default form + some "hello this is test email" text.

Then I bought @andreyka26.com email domain, transferred it, because account was flagged as missing some security/privacy/compliance points. And it still had these "violation" markers, however email is legit, it works, and I want to TEST SEND it to my personal email.

I submitted a complaint to them asking what is wrong with my acc, why can't I send even test email?

The response is "seek for other vendor". Like no way back, no trial to fix, no explanation what exactly I violated. Now again I would need fucking 2-3 days of my life to migrate (if that is possible at all, idk), reintegrate to the blog, etc etc.

Very bad feedback from my side. If you consider mailchimp -> reconsider.

https://paperdraw.dev/

Try this! This is system design diagram tool that can show you the traffic, and prove that it will handle certain rps.

It is paid after 3 simulations, so I gonna vibe code it. It will be a good thing for Messenger article + I will give it to you once I am done, so you can practice with me.

For people who didn’t know - I am working on my pet project for logging/tracking/analysing symptoms. App is designed only for my own needs.

Yesterday I got understanding that we are far from being replaced still. The app is fully vibe coded, I was only doing manual deployment to vm, I dont fully know how it works.

I am using claude in a very beginner mode, I gave him Claude.md, put sonnet4.6 and just explain what to do in single session, nothing advanced.


I added 2 features to react FE and nest BE (the easiest for ai to work with), and it broke ui in 2 places, one feature is just removed from ui silently. But the critical thing was that nest stopped starting up, so no backend.

It was trying to fix it for 20-30 mins, until I myself analysed what happened and gave him hint what can be wrong and then he found it.
Yes it is probably skill issue, but this is exactly the point. Random noname vibecoder would have skill issue as well. So even if we fully can trust ai, there is still skill needed to be able to properly set and maintain it so it does right thing and does not break your backend.

This leads me to the idea, that maybe QA aren’t done as I thought.

Right now with the vibe coding shit, code is cheaper than effort to validate what AI has produced. Since we cannot trust AI in testing (and in general) we need human being to ensure nothing is broken, all is working, etc.

And ofc security will be a thing. I mean mostly it can be automated as well, but there should be a human being ensuring it covered everything.

Daily (234/373 streak until LC cap)

BS problem, don't do it and don't waste your brain energy on it.

https://leetcode.com/problems/lexicographically-smallest-generated-string/description/?envType=daily-question&envId=2026-03-31

#daily #hard #nopattern

Do you know about ARP protocol in tcp/ip stack?
Address resolution protocol - is the way Ethernet resolves physical MAC address given Ip address.

Then the resolved MAC address is used to deliver the datagram to the physical device withing the LAN.

It is located on Link layer in Tcp/Ip layering, below Internet layer