Ishwar Chandra Tiwari

Problem-Solving Engineer
Frontend • Backend • DSA • System Design
Think first. Code later.
CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

Hi 👋 I’m Ishwar.

12+ years in software engineering.
I share DSA, system design, and real-world coding insights.

Building CodeWithIshwar 🚀

[Ishwar Chandra Tiwari @codewithishwar]

Simple code > Clever code.

The best engineers don't make things complicated.

They make complex things simple.

#CodeWithIshwar #SoftwareEngineering #CleanCode #Programming #DeveloperLife 🚀

[Ishwar Chandra Tiwari @codewithishwar]

Most microservices should be monoliths.

Most teams don't need distributed systems.

They need simpler systems.

Agree or disagree?

#SoftwareEngineering #SystemDesign

[Ishwar Chandra Tiwari @codewithishwar]

Software engineering and software interviews test different skills.The best engineers master both.#CodeWithIshwar #SoftwareEngineering #InterviewPrep

[Ishwar Chandra Tiwari @codewithishwar]

The best code:

Doesn't exist.

No bugs.
No maintenance.
No documentation.
No complexity.
Sometimes the most valuable commit is:
"Removed 2,000 lines of code."
#CodeWithIshwar #SoftwareEngineering 🚀

[Ishwar Chandra Tiwari @codewithishwar]

This week's learning:

The internet has no shortage of tutorials.

The shortage is people willing to struggle through building something from scratch.

Agree or disagree?

#FridayLearning #CodeWithIshwar #BuildInPublic #Programming #SoftwareEngineering 🚀

[Ishwar Chandra Tiwari @codewithishwar]

SOLID Principles make code scalable, maintainable, and easier to debug.

#codewithishwar #SOLID #CleanCode #SoftwareEngineering #Programming #Java #Backend #SystemDesign #Coding #Developers #TechTwitter #100DaysOfCode #Architecture #FullStackDeveloper

[Ishwar Chandra Tiwari @codewithishwar]

Node.js is single-threaded, but concurrency issues still happen.

Race conditions and overlapping async operations are real challenges in scalable systems.

That’s why mutexes, transactions, and Redis locks still matter 🚀

#NodeJS #JavaScript #BackendDevelopment #codewithishwar

[Ishwar Chandra Tiwari @codewithishwar]

Git won the popularity war.
But Mercurial powered massive engineering workflows at Meta Platforms and Mozilla.
🚀 New newsletter:
“Why Mercurial Still Matters in 2026”
https://t.co/ghKfKjDBxF
#Mercurial #Git #SoftwareEngineering #CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

JavaScript is single-threaded.

So why do race conditions still exist? 👀

Because async JavaScript is all about execution order.

Event Loop → Promises → Microtasks → Race Conditions.

That’s the real game.

#CodeWithIshwar #javascript #nodejs #reactjs

[Ishwar Chandra Tiwari @codewithishwar]

Most devs don’t struggle with JavaScript.

They struggle because they ignore what’s under the hood.

JS =
• Closures (memory)
• Event Loop (async)
• Prototypes (inheritance)
• Coercion (weird but powerful)

#JavaScript #WebDev #Programming #CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

A simple integer broke my program.

Two threads:
+1 and -1
Expected: 0
Actual: ❌ random

Because value++ is NOT atomic.
It’s:
Read → Modify → Write

Threads can interleave at any step → race condition.

#Concurrency #Multithreading #CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

Redis looks simple — just key-value storage.

But underneath, it’s powered by smart data structures: Strings, Hashes, Lists, Sets, Sorted Sets.

That’s why Redis isn’t just fast — it’s a data structure engine for real-time systems 🚀

#Redis #DSA #SystemDesign #CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

There is NO perfect system design.

Netflix scaled → changed architecture
Amazon trades consistency for availability
Uber keeps redesigning systems
Reality:
👉 Every system is a trade-off
#SystemDesign #Backend #Scalability #codewithishwar

[Ishwar Chandra Tiwari @codewithishwar]

Most developers use indexes. Very few truly understand how they work https://t.co/2p0J7bLSB6

[Ishwar Chandra Tiwari @codewithishwar]

🌐 Type a URL → DNS kicks in 🌐

Cache → Resolver → Root → TLD → IP

⚡ Cache = fast
🐢 No cache = slow
#dns #systemdesign #systemdesign #dns #backend #programming #codewithishwar

[Ishwar Chandra Tiwari @codewithishwar]

Scaling too early is a mistake.
You don’t scale your system—you scale your problems.
#SystemDesign #Scalability #BackendEngineering #SoftwareEngineering #CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

Production was down.

Everything looked normal.

That’s when you know:

You’re solving a puzzle, not debugging.

#programming #systemdesign #codewithishwar

[Ishwar Chandra Tiwari @codewithishwar]

Most devs write code. Few understand what happens after.

Your code → AST (Abstract Syntax Tree), not executed as text.

Example: a = 2 + 3 * 4 → * before +

Code = string
AST = logic
#CodeWithIshwar #Programming #Developers

[Ishwar Chandra Tiwari @codewithishwar]

🧠 Thread vs Async vs Queue

Not alternatives. Different answers.

🧵 Threads → parallel work
⚡ Async → don’t block
📦 Queue → do it later
Real systems use all three.

Scalability = choosing based on the problem.

#SystemDesign #Concurrency #CodeWithIshwar

[Ishwar Chandra Tiwari @codewithishwar]

Check out the latest article in my newsletter: 🧠 Mark & Sweep Isn’t a Language Feature. It’s a System Design Pattern. https://t.co/K9yv9MNthp via @LinkedIn