Ranjan Kumar
AI & ML Engineer · Author · Educator
I help AI builders design, build, and ship production-grade AI systems that actually work, cost-effectively, through hands-on writing, books, and practical engineering guidance.
Latest Posts
View all →How to Rerank Retrieval Results with a Cross-Encoder
Build a two-stage search pipeline and measure the reranking gain yourself, in NDCG@10, on your own machine.
ai-engineeringHow to Rerank Retrieval Results with a Cross-Encoder
Build a two-stage search pipeline and measure the reranking gain yourself, in NDCG@10, on your own machine.
ai-engineeringFastAPI + LangGraph: What a Client Disconnect Commits
Your handler's shape, not your checkpointer, decides whether an interrupted agent run stops, finishes, or leaves a charge nobody recorded.
ai_mlThe ChatML Handbook, Second Edition: What Won and What Fragmented
The role-tagged message list became the universal format. The specific tokens did not. The second edition says so in the preface, and rebuilds the practical half around a support bot that actually runs.
My Books
The ChatML (Chat Markup Language) Handbook
A Developer’s Guide to Structured Prompting and LLM Conversations
Learn how to structure prompts using ChatML for predictable, production-ready LLM behavior.
Building Real-World Agentic AI Systems with LangGraph
Designing, building, evaluating, and shipping stateful, durable, multi-agent systems on LangGraph 1.x
A practitioner's guide to designing, deploying, and operating reliable agentic AI systems in the real world.
The Chat Templates Handbook
A Developer’s Guide to Jinja, apply_chat_template, and Rendering Model-Ready Prompts
A curated collection of battle-tested templates for common LLM tasks and workflows.
My Toolkit
A collection of tools I've built to boost productivity and simplify workflows.
Developer & AI Tools
Test Your Knowledge
Quiz yourself on AI engineering, observability, and production LLM systems
MedhaV - मेधावी
Start every day with clarity
Imagelly
AI-Based SaaS Image Edit/Enhancement Tool
Mermaid Diagram Generator
Create flowcharts, sequence diagrams, and more
MermAniSt — Mermaid Animation Studio
Turn Mermaid diagrams into animated presentations
LinkedIn Text Formatter
Format your LinkedIn posts with bold, italic, and more
MarkMelon: Markdown Editor
Edit, generate docs from Markdown and more
Slides Creator from Markdown
Generate beautiful presentations from Markdown
What I Write About
AI & ML Engineering
Production-ready AI systems, LLMs, and machine learning deployment strategies.
System Design
Scalable architectures, distributed systems, and infrastructure for AI applications.
Real-World Projects
Case studies, lessons learned, and practical insights from production deployments.
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