Hi, I'm Sanjoy Chattopadhyay.

I make weird ideas
behave like working software.

AI + BACKEND + CHAOS — not always in that order.

Mostly building with AI, backend systems, a little blockchain, and a healthy amount of curiosity, debugging, and "let me just try one more thing."

GitHub LinkedIn Resume

01 About

Education

2024 — 2026

M.Tech in Computer Science & Engineering

National Institute of Technology, Durgapur

CGPA: 9.0

2018 — 2022

B.Tech in Computer Science & Engineering

Birbhum Institute of Engineering & Technology, West Bengal

CGPA: 9.32

2018

12th Standard

West Bengal Board of Secondary Education

86%

2016

10th Standard

West Bengal Board of Secondary Education

91.4%

Experience

2025

Data Science Intern, Indian Army

Built predictive maintenance ideas around military vehicle health, analytics, and field-ready dashboards at Panagarh Military Station.

Real-world impact

2022 — 2023

Graduate Engineer Trainee, HCLTech

Worked on backend systems, enterprise workflows, microservices, and the kind of bugs that teach patience better than any motivational quote.

Industry chapter

Things I Somehow Pulled Off

GATE 2024 CS — managed to negotiate a 97.18 percentile with the exam gods
Indian Army Innovation Contest 2025 — reached Top 20 nationally, which still sounds made up when I say it out loud
Ex-SDE at HCLTech — spent 2+ years in the software mines and came back with stories
67+ Open Source Projects — my GitHub is basically a digital hostel room, but productive
CodeChef — solved 74 problems across 15 contests and definitely argued with the compiler more than once
GeeksforGeeks — published DS/Algo articles after overthinking arrays, trees, and life
LeetCode — got weirdly comfortable with bit manipulation and binary search at suspicious hours

Tech Stack

Languages

PythonJavaScriptJavaC++SolidityCSQL

AI / ML

LangChainLangGraphMCP AgentsRAGFAISSOpenAIGroqCNNVision Transformers

Backend & Frontend

FastAPINode.jsExpressReactStreamlitSpring BootServlets/JSP

Blockchain

EthereumSolidityZK ProofsSmart ContractsERC-20/721/1155

Databases & Tools

MongoDBSQLiteSQL ServerGitDockerRenderGitHub Pages

03 Projects

Built from real-world problems. Click any project for full details.

04 Blogs & Student Resources

Guides, reflections, and curated resources for students and builders.

05 Books That Shape My Thinking

06 Interview Journeys

A memory-based snapshot of the rounds I cleared, the DSA themes I handled, and the habits that kept saving me.

The pattern that helped me most was simple: explain the brute-force idea first, improve it calmly, test edge cases out loud, and never let panic write the final answer.

TCS

Selected

TCS rounds felt like a test of clean basics. The trick was not doing magic, just being reliable under pressure.

DSA Themes I Tackled

Array traversal, sorting logic, and string processing
Binary search style thinking when constraints got tighter
Edge-case handling without overcomplicating the code

How I Cracked It

Kept solutions readable and explained every optimization step
Spoke through test cases before finalizing the answer
Focused on correctness first, polish second

Wipro

Selected

Wipro felt like one of those rounds where consistency mattered more than trying to look brilliant.

DSA Themes I Tackled

Linked list and stack-based problem patterns
String transformations and logic-heavy dry runs
Time-complexity discussion after the first solution

How I Cracked It

Started with the simplest valid solution and improved from there
Used examples while explaining so the interviewer could follow the flow
Stayed calm when asked to optimize on the spot

Intel

The technical rounds went well — bit manipulation, recursion, complexity tradeoffs. Made it through to HR and didn't make it past. A reminder that how you present yourself matters just as much as how you code.

What I Cleared

DSA: bit manipulation, recursion, and graph-style reasoning
Technical: depth questions on code correctness and space optimization
Explained tradeoffs clearly — reached the HR stage

What I Learned From the Loss

Technical excellence alone does not close the loop — fit and communication do
HR rounds at product companies are structured evaluations, not small talk
I made storytelling and self-presentation a serious part of prep after this

Tech Mahindra

Selected

This one rewarded practical thinking. Clean fundamentals and a calm walkthrough did most of the heavy lifting.

DSA Themes I Tackled

Hashing, matrix traversal, and greedy-style choices
String manipulation with corner cases
Simple logic done correctly and efficiently

How I Cracked It

Did not jump to fancy solutions where simple ones worked
Verified every answer with small sample inputs
Kept the communication structured and grounded

HCLTech

Selected

HCLTech was where preparation met opportunity. It was one of the first times I felt interview practice turning into something real.

DSA Themes I Tackled

Arrays, trees, and recursion with implementation clarity
Problem-solving mixed with Java and backend discussions
SQL and system thinking alongside coding fundamentals

How I Cracked It

Balanced coding answers with practical backend understanding
Explained not just what the code did, but where it would be useful
Stayed honest when I needed a second to think

Indian Army

Selected

This experience felt different. It was less about textbook answers and more about whether my thinking could solve something meaningful.

Technical Themes I Tackled

Data reasoning, predictive logic, and system usefulness
Structuring information clearly for high-stakes use cases
Problem-solving under practical constraints, not just coding theory

How I Cracked It

Focused on impact, clarity, and real deployment value
Explained technical ideas in a grounded, usable way
Made the solution feel relevant to the actual problem, not just technically correct

TimePay

Made it through every technical round — DSA, coding, and system questions. The HR round was where it ended. Taught me that technical skill alone is not the whole game.

What I Cleared

DSA round: array manipulation, searching, and optimization problems
Technical interview: core CS fundamentals and practical problem-solving
Reached the final HR evaluation stage

What I Learned From the Loss

HR rounds test communication, fit, and story — not just skill
Prepare your narrative as seriously as your algorithms
Every door that closes is a calibration, not a verdict

Oracle

Cleared the DSA round confidently. The DBMS Administration round went deeper than I was prepared for — it was a valuable lesson in knowing the full stack of what you claim to know.

What I Cleared

DSA round: data structures, complexity analysis, and pattern-based problems
Demonstrated strong algorithm thinking and code clarity

What I Learned From the Loss

Oracle-level DBMS goes far beyond queries — indexing, locking, and administration
Depth matters as much as breadth when the role is data-heavy
I went back and rebuilt my DBMS foundations from the ground up after this