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From Beldanga to Building AI Products: My Dev Journey

How I went from self-teaching code during the 2020 pandemic to building AI systems, competing in national hackathon finals, and shipping open-source tools tested by real CS students.

Sayan Dutta
Sayan Dutta
Full-Stack Developer & AI Enthusiast · IIT Patna

BS-MS student in CS & Data Analytics at IIT Patna. Building AI-powered products, LLM tools, and open-source software that solves real problems.


Everyone starts somewhere. For me, it was a laptop in Beldanga, Murshidabad, during the 2020 lockdown — self-teaching C from a YouTube playlist with no mentor, no coding community nearby, and nowhere else to be. I had no idea that a few years later, I'd be at IIT Patna building custom language models, integrating three different AI APIs into a single system, and shipping open-source tools tested by real CS students.

This is the honest story of how that happened — the wins, the late nights, the failed projects, and the mindset shifts that made all the difference.

3+Years of building
10+Projects shipped
5★HackerRank rating

IIT Year One: Formalising the Foundation

I arrived at IIT Patna in 2025 already knowing how to write code. Five years of self-teaching since 2020, two years of Diploma in Engineering in Kolkata, a deployed full-stack application — that was the baseline. What IIT did was formalise it. Suddenly the things I'd been doing by instinct had names, proofs, and complexity bounds.

The first-semester curriculum hit hard in a different way than I expected. Not because the concepts were new — I knew what a linked list was — but because the rigour was. I remember spending four hours debugging a linked list reversal in an assignment and realising the off-by-one error only after writing out the pointer state on paper. That kind of systematic thinking was the real upgrade IIT delivered.

"The best way to learn to code is to build something you actually want to exist." That realisation started in 2020. IIT gave it structure, vocabulary, and peers who pushed it further.

By the end of the first semester I had a stronger grasp of algorithms, data structures, and systems theory than four years of self-study had given me. More importantly, I had classmates who were as obsessed with building as I was.

C C++ Algorithms Systems Theory Git

Diploma Years: Going Full-Stack

Before IIT, during my Diploma in Engineering in Kolkata (2023–2025), is where I went from writing scripts to building real applications. I picked up JavaScript almost by accident — I wanted to build a simple web dashboard for tracking my study hours, and vanilla JS was the fastest path. Within a month I was deep into Node.js, Express, and React.

The Pathology Admin Panel

My first serious project came from an unexpected place. A relative who ran a pathology lab mentioned how painful it was to manage patient records, billing, and test reports using a patchwork of spreadsheets and paper forms. I offered to build something better.

What followed was three months of weekend work during the Diploma — designing a MySQL schema from scratch, building a REST API with Express, creating a React frontend with chart-based analytics, and handling edge cases I hadn't anticipated (like what happens when a test has multiple billing codes, or when a report needs to be regenerated without overwriting the original).

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Lesson learned: Real-world projects are 10× harder than tutorials because users have requirements that don't show up in any documentation. Embrace that complexity — it's where the real learning happens.

The panel went live and the lab still uses it today. That feeling — watching a non-technical person navigate something I built, with zero confusion — was more motivating than any grade.

React.js Node.js Express.js MySQL REST APIs

The AI Turn

Toward the end of my Diploma years, I started noticing a pattern in my study group: everyone was struggling with the same core CS subjects — OS concepts, DBMS theory, algorithm complexity — and the existing resources either dumbed things down too much or assumed too much background knowledge.

Around the same time, the LLM explosion was happening. GPT-4 came out. Open-source models like LLaMA were being released. I started wondering: what if a language model was trained specifically on these CS topics?

Building Blix.ai

That question became Blix.ai — a privacy-first, self-hosted AI tutor for computer science students, currently running in closed beta. The goal was simple in concept but hard in execution: a model that could answer both theoretical questions ("explain the difference between process and thread") and practical coding questions ("why does this semaphore implementation deadlock?") with the depth of a senior TA.

Month 1
Dataset curation
Scraped, cleaned, and structured Q&A data across OS, DBMS, DSA, Networks, and AI/ML from textbooks, lecture notes, and Stack Overflow threads.
Month 2
Fine-tuning pipeline
Set up a fine-tuning pipeline on a quantised base model using LoRA adapters. Ran experiments on Colab TPUs burning through free quota daily.
Month 3
Inference server & frontend
Built a FastAPI inference server, optimised for low-latency streaming responses, and a clean React chat interface. Self-hosted on a personal VPS.
Month 4+
Closed beta with classmates
Opened Blix.ai to a closed group of IIT Patna classmates for beta testing. Iterated based on failure cases — the model was confidently wrong about deadlock conditions initially.
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Hardest part: Getting the model to say "I don't know" instead of hallucinating a plausible-sounding but incorrect answer. This required careful RLHF-style preference data — teaching the model that an honest "I'm uncertain" is better than a confident wrong answer.

Blix.ai is running in closed beta, free for all testers, and aligned with UN SDG4: Quality Education for All. The code is open-source. If it helps even a few students pass their operating systems exam, it was worth every debugging session.

LLMs Fine-tuning LoRA FastAPI Self-hosting HuggingFace

Hackathons: Shipping Under Pressure

Nothing teaches you to build fast like a hackathon. I've competed in five national-level AI hackathons so far, reached the finals in two, and learned something important from each one — including the ones where we didn't place.

The biggest lesson: your first idea is almost never your best idea. The teams that win usually pivot hard somewhere in hour four or five, after they've built something and realised what the actual interesting problem is.

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Hackathon framework I swear by: Spend the first hour just talking. Don't touch a keyboard. Agree on what problem you're actually solving and who the user is. Then build the smallest possible version that demonstrates the core value. Polish is for the final two hours only.

Competing with a team also taught me things about collaboration that solo projects can't. When you're tired at 2am and someone else's code breaks your integration, you learn a lot about communication and version control very quickly.

The AI Integration Hub

After working extensively with OpenAI's API for Blix.ai, I noticed a recurring pain point: every project that wanted to use AI had to re-implement the same boilerplate — authentication, rate limiting, error handling, response parsing, model selection logic. And if you wanted to switch providers or route to different models based on the task, you were essentially rewriting your integration layer from scratch.

So I built the AI Integration Hub — a single API layer that sits in front of OpenAI, Anthropic, and Google Gemini. You send one request, specify a task type, and the hub routes to the best model, handles retries, caches where appropriate, and returns a normalised response regardless of which provider served it.

// Before: vendor-specific boilerplate
const response = await openai.chat.completions.create({
  model: "gpt-4o",
  messages: [{ role: "user", content: prompt }]
});

// After: one interface, any provider
const response = await hub.complete({
  task: "code_review",
  prompt,
  // hub picks the best model automatically
});

The Hub now supports three providers, handles ~200 requests/day in testing, and has saved me personally from vendor lock-in twice. It's the kind of infrastructure that doesn't seem glamorous until you've had to rewrite it.

OpenAI API Anthropic API Gemini API Node.js Redis Docker

What I'd Tell My 2020 Self

Looking back across three-plus years of active building and ten-plus projects, a few things stand out as genuinely important:

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What's next: Blix.ai v2 is in development — targeting a public launch in February 2027 — with a larger dataset, better factual grounding, and multi-turn conversation memory. I'm also exploring research in AI alignment and planning to contribute to open-source LLM tooling in the coming months. If you're building something interesting in this space — let's talk.

Final Thoughts

The journey from a curious kid in Beldanga teaching himself C during a lockdown to building AI-powered products at IIT Patna hasn't been linear. There have been months where nothing shipped, projects that got abandoned halfway, and ideas that seemed brilliant at 1am and terrible by morning.

But the compounding effect of consistent building is real. Every project teaches you something the next one needs. Every failure rules out a direction that would have wasted more time later. And every tool that someone actually uses — however small — is a reminder of why this is worth doing.

If you're early in your own journey and this resonated, I hope it's useful. If you want to talk about anything covered here — Blix.ai, the AI Hub, hackathon strategy, or just what it's like studying CS at IIT Patna — reach out. I'm always happy to chat.

Sayan Dutta
Sayan Dutta
Full-Stack Developer & AI Enthusiast · IIT Patna
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