So remember, whenever you have race conditions situation in your system design, blindly "read data by application, make decision in application and then write back to storage" does not work.

You will need to use some additional things to make it work, and we are going to talk about it in the article that currently "work in progress"

Daily (325/373 streak until LC cap)

Not bad problem, has well known pattern that I haven't seen for a very long time in daily problems. Definitely recommended. It is not hard

https://leetcode.com/problems/number-of-substrings-containing-all-three-characters/description/?envType=daily-question&envId=2026-06-30

#daily #medium #pattern

Daily 326 streak

Nice problem, graphs (in some sense), not very very hard, but pretty tough. Recommend, it uses 2 common patterns.

https://leetcode.com/problems/find-the-safest-path-in-a-grid/description/?envType=daily-question&envId=2026-07-01

#daily #medium #pattern

From now on I switch pattern Daily (X/373 streak until LC cap) to Daily X streak as we have got cap, and I don't have much goal now except just keep going and keep skill

Feel sorry for overheated EU, but here it is cold enough to make me wear jacket at night, now 17 degrees + wind. Amazing summer, love it in Dublin

Daily 327th day streak

Exactly same pattern as was yesterday, just a bit different problem semantics. Definitely worth of recalling the patterns, as they are used in the interviews.

https://leetcode.com/problems/find-a-safe-walk-through-a-grid/description/?envType=daily-question&envId=2026-07-02

#daily #medium #pattern

this is one of bunch of interesting things that are used in my current project in a very tricky manner, by ex-googlers.

I now have exactly same vibe/feeling as I had at my first company (2018, small 60 people outsource company), where I had techlead with 10+ years of experience, with already rejected Amazon and Microsoft offers: everything looks unknown and/or complicated, you overloading your brain with a lot of stuff that you are supposed to know. Understanding that people around are quite fluent in in it comparing to you hurts even more.