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 →LangGraph Names the Guarantee, Not the Unit
Seven parts of measurement found one recurring shape: the bound is real, it is correctly enforced, and it is scoped to something you did not assume.
ai-engineeringLangGraph Evals Test the Answer, Not the Thread
One approval decision fired the charge three times. Both output assertions passed, and every checkpoint on the thread recorded nothing about it.
ai-engineeringLangGraph's recursion_limit Bounds Depth, Not Width
A limit of 4 let 1,000 workers run. The bound is real, it is enforced, and it counts the one axis the runtime knows how to count.
ai-engineeringLangGraph Compaction Deletes the View, Not the Record
Your summarizer removed the message from state. Eighteen checkpoints on disk still have it, and an ordinary fork puts it back.
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.