Dev Chawla

MERN Stack Developer | Coding daily | Building & learning in public

[Dev Chawla @DevChawla04]

Attended the React meetup at XoxoDay HQ and won a prize in the tech quiz

[Dev Chawla @DevChawla04]

@kirat_tw 🚀 100x Web Dev Bootcamp

Today I learned:

✅ useRef in React
✅ Built a Stopwatch

[Dev Chawla @DevChawla04]

Just completed Week 18 of the 100xDevs Bootcamp by @kirat_tw 🚀

Today’s learnings:
• Bootstrapping React projects using Vite ⚡
• Why Vite is faster with blazing fast HMR
• Creating React apps using npm create vite@latest
• Understanding React Components and reusable UI building blocks

#ReactJS #WebDevelopment #JavaScript #100xDevs

[Dev Chawla @DevChawla04]

Just completed Week 18 of the 100xDevs Bootcamp by @kirat_tw 🚀

Today’s learnings:
• Bootstrapping React projects using Vite ⚡
• Why Vite is faster with blazing fast HMR
• Creating React apps using npm create vite@latest
• Understanding React Components and reusable UI building blocks

#ReactJS #WebDevelopment #JavaScript #100xDevs

[Dev Chawla @DevChawla04]

Just learnt how centralized exchanges like Binance/Backpack work under the hood 🚀
@kirat_tw

Key learnings today from the exchange architecture deep dive:

• Built understanding of SPOT exchanges & orderbooks
• Users place bids (buy) and asks (sell) just like real-world brokers
• Trade executes when bid & ask prices overlap
• Orderbooks are stored in-memory for ultra low latency
• Databases are used for persistence, not real-time matching
• Designed schemas for users, balances, trades & markets
• Learnt how backend communicates with matching engine
• Understood why concurrency & speed matter in exchanges

[Dev Chawla @DevChawla04]

Just attended Week 17 of the 100xDevs Bootcamp by @kirat_tw 🚀

Today’s focus:
• Explored how SWE-bench works
• Understood benchmark creation for evaluating LLMs
• Started cloning SWE-bench concepts
• Building our own benchmark
• Goal: Can LLMs solve easy coding tasks effectively?
• Went through SWE-bench dataset structure & inspected ~85% of the fields
Super interesting dive into AI evaluation systems, datasets, and benchmarking ⚡📊

[Dev Chawla @DevChawla04]

Just hit my first 100 followers 🎉
Small milestone, but a huge motivation boost.
Thanks to everyone following the journey

[Dev Chawla @DevChawla04]

Just learnt how centralized exchanges like Binance/Backpack work under the hood 🚀
@kirat_tw

Key learnings today from the exchange architecture deep dive:

• Built understanding of SPOT exchanges & orderbooks
• Users place bids (buy) and asks (sell) just like real-world brokers
• Trade executes when bid & ask prices overlap
• Orderbooks are stored in-memory for ultra low latency
• Databases are used for persistence, not real-time matching
• Designed schemas for users, balances, trades & markets
• Learnt how backend communicates with matching engine
• Understood why concurrency & speed matter in exchanges

[Dev Chawla @DevChawla04]

@sina_samiii @kirat_tw Yes, this course is helpful

[Dev Chawla @DevChawla04]

Just attended Week 17 of the 100xDevs Bootcamp by @kirat_tw 🚀

Today’s focus:
• Explored how SWE-bench works
• Understood benchmark creation for evaluating LLMs
• Started cloning SWE-bench concepts
• Building our own benchmark
• Goal: Can LLMs solve easy coding tasks effectively?
• Went through SWE-bench dataset structure & inspected ~85% of the fields
Super interesting dive into AI evaluation systems, datasets, and benchmarking ⚡📊

[Dev Chawla @DevChawla04]

Week 16 of Harkirat’s 100x Bootcamp ✅
@kirat_tw
📌 Key Learnings
-> TypeScript adds type safety on top of JavaScript
-> Code doesn’t run directly — it compiles to JavaScript
-> Understanding basic types: number, string, boolean, etc.
-> How to type:Function arguments
Return values
-> Type inference reduces the need for explicit types
-> Using interfaces to define object structures

[Dev Chawla @DevChawla04]

💡 Max Product Subarray in JS

Track both max & min at each step

🔁 Swap when current < 0
📈 Update maxSoFar & minSoFar
🏆 Keep global result

#JavaScript #Coding #LeetCode

[Dev Chawla @DevChawla04]

Solved Count Inversions

Split array into smaller parts (like merge sort)
Sort left and right parts
While merging, compare elements
If left element is bigger than right → it's an inversion
Count how many elements are left in the left part
Add that to total count
Keep merging until array is sorted

[Dev Chawla @DevChawla04]

💡 Missing & Repeating Number

Given an array of size n with numbers from 1 to n:
👉 One number is missing
👉 One number repeats
🔍 Approach:
Create a frequency array of size n+1

Count occurrences of each element

Traverse 1 → n:
• freq[i] == 0 → missing
• freq[i] == 2 → repeating
Return [repeating, missing]

[Dev Chawla @DevChawla04]

Merging two sorted arrays in-place 👇

• Start from the end to avoid overwriting values
• Use 3 pointers:
i = last valid in nums1 (m-1)
j = last in nums2 (n-1)
k = last position in nums1 (m+n-1)
• Compare nums1[i] & nums2[j]
• Place the larger at nums1[k]
• Move pointers accordingly
• Stop when nums2 is fully merged

[Dev Chawla @DevChawla04]

Merging intervals efficiently

• Sort intervals by start time
• Initialize result with first interval
• Traverse remaining intervals
• If overlap (current start ≤ last end) → merge
• Else → add as new interval
• Keep updating end with max value

[Dev Chawla @DevChawla04]

Solved the 3Sum problem 💡

=> Sort the array
=> Fix one number (loop through array)
=> Use two pointers: left (next index) and right (end)
=> Check sum of three numbers
=> If sum = 0 → store the triplet
=> If sum < 0 → move left pointer forward
=> If sum > 0 → move right pointer backward
=> Skip duplicates to avoid repeating results

#coding #javascript #leetcode

[Dev Chawla @DevChawla04]

🚀 Solving Majority Element (&gt; n/3)

Approach 👇
• Use a hashmap to count frequency of each element
• Loop through array → store counts
• Traverse map → check elements &gt; ⌊n/3⌋
• Push valid elements to result

#JavaScript #DSA #Coding

[Dev Chawla @DevChawla04]

Solved Pascal's Triangle Problem

Approach:-
Start with an empty array to store all rows
Each row has i + 1 elements
Use previous row to calculate current values
Edge elements are always 1
Inner elements = sum of two values above (left + right)
Use 0 fallback when indices don’t exist
Push each row into the result
Return the full triangle

[Dev Chawla @DevChawla04]

Week 14 of Harkirat’s 100x Bootcamp ✅ @kirat_tw

Key takeaways:

🔐 Password hashing — never store plain text passwords
🧂 Salts — adding randomness for stronger security
🧪 Zod validation — clean, type-safe form validation