Rahul

I have seen more systems struggling because of wrong code than slower ones. The fact remains, most engineers optimise too early. About 8 years ago, my principal engineer once told me: Performance is almost always the last thing you should be thinking about. As an SDE-2, this did not make sense :) After a few follow-ups, I understood why he meant that. The order that actually matters is this. First, is the code correct? Does it do what it is supposed to do? Second, can someone maintain it six months from now without wanting to quit? Third, is it fast to read and write? Only after all three does performance even enter the conversation. The reason this order exists is simple. A fast, unmaintainable codebase is a liability. A performant-but-wrong system is worse than a slow, correct one. You cannot optimise your way out of a bug. Now, this is not universally true. Databases, high-frequency trading systems, and real-time embedded software are domains where performance is a first-class concern from day one. But those are the exceptions, not the default assumption you should bring to every PR. What is certainly true is that for most codebases, premature optimisation adds complexity, reduces readability, and solves a problem that does not exist yet. So, write correct code first. Then clean it. Then, only if the profiler gives you a reason, make it fast.

@aliwhosane @championswimmer Exactly! What's the logic behind uppercasing it before hashing?!

@championswimmer I still don't get the logic of uppercasing everything in password

The stupidity of people who read password hashing for 2 min in a CS101 class and never cared to follow through with any better understanding of cryptography. 🤦‍♂️ This is so easily explained by the fact that HSBC was just doing hash(uppercase(pass)) before and will do just hash(pass) now

Claude code source code has been leaked via a map file in their npm registry! Code: …a8527898604c1bbb12468b1581d95e.r2.dev/src.zip

bhai ek dam lodu Chand app he jiomart 🤡 tum buttermilk search karo to chini, biscuit, cheese falana dhikana sab dikha dega lekin result me buttermilk nhi dikhayega.. or product out of stock he ye sab delivery wala ghar aake batayega..

The Java security practice that still catches even senior developers in 2026: Input validation & sanitization done right: One of the most critical (and frequently neglected) areas in Java applications is proper input validation and sanitization. Failing here opens the door to injection attacks, XSS, and data corruption - even in modern Spring Boot / microservices setups. Best practice in 2026: Validate early and strictly (whitelists > blacklists) Use OWASP Java Encoder / Validator for sanitization , custom constraints) Combine with Bean Validation (@NotNull,@Pattern Never trust user input - even from "trusted" internal services

@RajneetiTadka @kapsology Rules banane wale hi lack civic sense

@kapsology Civic sense improves when rules are enforced consistently and public infrastructure supports better behaviour.

India will always remain a third-world country because people with zero civic sense are taking over our cities. There are no penalties for being uncivilized in this country; in fact, it is seen as a matter of pride by a certain section of society. Remember, this has nothing to do with education.

@rameshsrivats Lodu, tu har roz ek hi auto se jaata hai kya?

Auto rickshaws charge a minimum fare that is for 2 kilometers. If I travel only 1.5km, the unused 500 meters should carry forward into the next auto ride.

If you are looking to upskill, not just clear interviews, add hard questions like these: Dynamic Programming / Advanced DP: 87 Scramble String 1547 Minimum Cost to Cut a Stick 312 Burst Balloons 446 Arithmetic Slices II 956 Tallest Billboard Graphs / Shortest Path / Union Find: 269 Alien Dictionary 332 Reconstruct Itinerary 685 Redundant Connection II 778 Swim in Rising Water 2092 Find All People With Secret Trees / Recursion / Divide and Conquer: 124 Binary Tree Maximum Path Sum 297 Serialize and Deserialize Binary Tree 968 Binary Tree Cameras 114 Flatten Binary Tree to Linked List 1373 Maximum Sum BST in Binary Tree Intervals / Greedy / Heaps: 218 The Skyline Problem 759 Employee Free Time 630 Course Schedule III 502 IPO 2402 Meeting Rooms III Strings / Backtracking / Parsing: 51 N-Queens 212 Word Search II 301 Remove Invalid Parentheses 224 Basic Calculator 65 Valid Number Stacks / Monotonic / Hard Simulation: 42 Trapping Rain Water 84 Largest Rectangle in Histogram 85 Maximal Rectangle 895 Maximum Frequency Stack 772 Basic Calculator III Sliding Window / Hashing / Advanced Arrays: 76 Minimum Window Substring 239 Sliding Window Maximum 992 Subarrays with K Different Integers 41 First Missing Positive 4 Median of Two Sorted Arrays Design / Data Structures: 460 LFU Cache 432 All O`one Data Structure 381 Insert Delete GetRandom O(1) Duplicates allowed 895 Maximum Frequency Stack 642 Design Search Autocomplete System If you do: 1. 10 patterns x 3-5 hard problems each 2. 15-20 design-heavy coding questions 3. Revise the brute force, better, optimal path for every problem 4. Write the core template from memory 5. Revisit the same hard problem after 7 days without seeing notes --- You will gain way more than interview prep. Cause hard questions do something easy questions usually do not: They expose where your thinking breaks. Maybe your recursion is weak Maybe your state design in DP is weak Maybe you panic when multiple concepts combine Maybe you know heaps, but not when to use them with greedy Maybe your code works, but your edge case handling is poor That is the real value. Hard problems are not just for getting selected. They force you to think in systems. They improve patience. They teach decomposition. They make medium problems feel boringly easy later. A lot of people say: “I have solved 500 questions.” But if they avoided hard problems, many times what they really did was repeat the same 12 ideas in different clothes. For real upskilling: Solve by pattern Struggle honestly Read editorials deeply Re-code without help Revise after forgetting

@joelkaka @Nithin0dha No, banks use SMS permission to profile you and your activity from other banks.

@Nithin0dha I think banks ask sms - to auto read OTPs and auto fill contacts - to send money to your contacts as you can do it now phone calls - no , can't think of anything

I don't use net banking apps on my phone because the mandatory permissions they ask for make no sense. Why does a banking app need access to my SMS, phone, contacts, etc., in the name of security, when not seeking invasive device permissions is, in fact, the global benchmark for cybersecurity. This is called the Principle of Least Privilege (PoLP). “Don't do unto others what you don't want done unto you” has been at the heart of the Zerodha philosophy. This is exactly why we've built Zerodha the way we have. Kite asks for ZERO permissions on mobile, for instance, and this is one of the big reasons why millions of people trust us. What has enabled us is SEBI's mandatory strong two-factor authentication framework strike the right balance between security and privacy.

Swiggy - Stop Fooling People!! . @Swiggy this is some next-level cashback scam design. You run a 20% DineCash campaign, I accumulate ₹4,723, and then suddenly: • It expires in 14 days • You allow only 5% redemption per bill • Cap ₹400 per visit So to redeem ₹4,723 I need to spend ₹94,000 in restaurants within 14 days. Be honest — this isn’t cashback. This is designed expiry. Stop marketing it as “rewards” when the system is clearly built so most of it dies unused. . #ccgeeks #ccgeek

Tech guy in Australia adopts a rescue dog. Dog has aggressive cancer. Months to live. Instead of accepting it, he spends $3,000 to sequence the tumor DNA. No biology degree. No lab. Feeds the data into ChatGPT and AlphaFold. Identifies mutated proteins. Matches drug targets. Designs a custom mRNA cancer vaccine. From scratch. A genomics professor reads it and is gobsmacked that a random dog owner did this. The hardest part? Ethics approval. Red tape takes longer than building the vaccine. Three months later it’s approved. First injection. Tumor shrinks. Dog’s coat becomes glossy again. Dog is alive and happy. Now the obvious question: If one guy with a laptop can do this for a dog… why aren’t we doing this for humans? One person. $3,000. Two AI tools. Just outperformed a process that normally takes pharma companies years. We’re about to cure a lot of diseases.

@SumitM_X Partitioning by time won’t help much if most queries filter by "chat_id". You’ll still hit multiple partitions. An index on "(chat_id, created_at)" or partitioning by "chat_id" (or hash) would better match that access pattern.

Since most queries look like this: SELECT * FROM messages WHERE chat_id = 874234 ORDER BY created_at The Tech Lead suggested: Lets partition messages table by time. What's your reply?

@myself__alien @javarevisited How would you split a single CSV? Memory is limited

@javarevisited My approach is , split the CSV into chunks deduplicate each chunk and sort the chunks and merge the chunks

Technical interview question: You have a huge CSV file (20 GB). You need to remove duplicate rows. Memory is limited. How would you approach this?

@gauravh1 Happens with Airtel too.

Late last night, I recharged my #RelianceJio prepaid number with the 349 plan, and this morning they sent me a reminder to recharge again! This can only happen with #Jio! 😂

@jig_corp ChatGPT ah response. 😭

@arpit_bhayani Perfect example of how cache locality beats theoretical complexity. Same O(n), very different real-world speed.

Let me talk about something obvious but with a bit of quantification... Theoretically, both arrays and linked lists take O(n) time to traverse, but here's what actually happens when you benchmark by summing 100k integers - Array: 68,312 ns - Linked List: 181,567 ns Summing an array is ~3x faster than LinkedList. Same algorithm, same complexity, but wildly different performance. The reason is cache behavior. When you access array[0], the CPU fetches an entire cache line (64 bytes), which includes array[0] through array[15]. The next 15 accesses are essentially free. Arrays hit the cache about 94% of the time. Linked lists suffer from pointer chasing. Each node is allocated separately by malloc(), scattered randomly in memory. Each access likely requires a new cache line fetch, resulting in a 70% cache miss rate. This is a good example of why Big O notation tells only part of the story. Spatial locality and cache-friendliness can make a 2-3x difference even when the theoretical complexity is identical. I am sure you would have known this, but this crude benchmark quantifies just how fast cache-friendly algorithms can be. Hope this helps.

@CaTarpit @bigulchugh ChatGPT ah reply 😭

@bigulchugh Axis really turned cashback into a loyalty test. First prove your dedication with ₹25K… then maybe we’ll talk about ₹250/500 cashback😂

To unlock “25% cashback” you first have to grind through base spends 🤯 New reward logic is next-level complicated. Want ₹500 cashback on a ₹2,000 payment? First spend ₹25,000 → Earn 1% = ₹250 base cashback → Only then you’re eligible for 25% cashback → Capped at 2× base cashback = ₹500 So basically… Spend ₹25K to unlock benefit on ₹2K 🤦‍♂️ Airtel Axis Card is officially DEAD with this update.

@SumitM_X What about >3 years?

Common Java interview questions for experience < 3 years - Why Strings are immutable? - Write your own immutable class - shallow vs deep cloning - How Can we write custom exception? - Producer/Consumer problem using wait and notify - noclassdeffound vs classnotfound exceptiont

@macxhui @HelloVyom @divyaporwal_ Pharmacy app pe number kaise milega? 😭

@HelloVyom @divyaporwal_ Apollo

This is literally not the correct way to ask for help. Using some Chrome extension to find my number and then messaging me directly is a breach of privacy. Whatever your situation is, this is not okay. If you genuinely need help, reach out through proper channels. I’m definitely not going to help in this way 🚫📵

@hsjjhamb @ShiprocketIndia True! Absolutely disgusting! And then the e-commerce companies block customer accounts, and often the sellers blame the customers for doing fraud even if they didn't. No wonder why India is a low-trust society.

@Dr_Spaghetti_Jr @ShiprocketIndia YES YES YES THIS IS WHAT HAPPENED THEY ARE INSTRUCTED TO DO IT TO SAVE VOLUME WEIGHT N COSTS. THAT IS WHAT HAPPENED WITH ME. BUT THEY ARE LYING ON TICKET RESOLUTION THAT THIS IS HOW CUSTOMER HANDED OVER EVEN AFTER I SHARED VIDEO MADE BY CUSTOMER.

received a call from them and the guy kept reading the script intentionally for me to give up and end everything. I AM TAKING YOU TO COURT @ShiprocketIndia