Featured
5 Reasons Your RAG System Fails in Production
RAG demos take an afternoon. Production takes months. Here are the 5 boring mistakes like bad chunking and context overflow that actually break RAG in the wild.
MR
Moyez Rabbani
Full Stack AI Engineer
About
I'm Moyez, a Full Stack AI Engineer at Deol Technologies, part of UB Realty, based in Kolkata. I build web applications and AI voice agents that answer calls and book appointments.
My work spans the interface, backend, and infrastructure. Recently, I've been moving a voice platform to LiveKit, building encrypted call recording storage, and fixing how the system handles simultaneous call updates.
I care about software that's easy to use and reliable in practice. Outside work, I read, build side projects, and go to the gym.
Work Experience
Deol Technologies (UB Realty)
Sep 2026 - Present
FluxxForward - IT Consulting | Lead Software Engineer
Aug 2024 - Apr 2026
Tak Decor
Oct 2023 - May 2024
Blogs
Featured writing first, then the newest notes on engineering, design, and building useful products.
Featured
Under the Hood of Vector Databases
A deep dive into embeddings, approximate nearest neighbors, and the architecture of similarity search, covering algorithms like HNSW, IVF, ANN, etc.
Featured
Designing RAG architecture for 10 million documents
Building RAG for 1,000 docs is a weekend project. At 10 million, it's a whole different story. In this article we break down everything to help you design one.
Featured
How Transformers Actually Work: One Sentence, Start to Finish
A step-by-step walkthrough of transformer architecture that follows one sentence from raw text to a translated output — with the attention math worked out by hand, not hand-waved.
Projects
Skills & Technologies
The languages, frameworks, and tools I use to take products from idea to production.
Anecdotes & Principles
Ideas I return to—kept as a small archive of reminders, observations, and hard-won truths.
Most saved
“Twenty years from now, the only people who will remember that you worked late are your kids.”
“Grow or die. Maintenance is a myth.”
“It’s far better to know why you failed than to be ignorant of why you succeeded.”
“The first principle is that you must not fool yourself—and you are the easiest person to fool.”
“Practice does not improve you. Corrected practice does.”
“You make mistakes; you're not a mistake.”
Let's Connect
Leave a message here, or send an email at moyezrabbani.work@gmail.com