Blog posts

2025

Green Padlock, Zero Headache: Let’s Encrypt SSL for Self-Hosted Dify

3 minute read

Published:

“Your app isn’t production until the padlock turns green.”
This guide merges the one-liner speed of the quick-start and the step-by-step clarity of the original long-form post.
Follow along and you’ll mint fresh Let’s Encrypt certificates, wire them into Dify’s Nginx, and set-and-forget auto-renewal—all in ~15 minutes.

A Field Guide & Benchmark for Similarity Search in RAG

5 minute read

Published:

“Facts are everywhere; the magic is fetching the right ones before your LLM starts talking.”
This deep‑dive turns that magic into engineering: a turn‑key benchmark + cookbook that lets you measure, compare, and future‑proof every similarity‑search trick you throw at Retrieval‑Augmented Generation (RAG).

LexSubLM-Lite: Lightweight Lexical Substitution That Runs Anywhere

3 minute read

Published:

Lexical substitution is one of those NLP tasks that seems simple until you try to do it well. You want a tool that can replace a word in a sentence with a substitute that makes sense, stays grammatically correct, and doesn’t rely on a 60GB language model. 😅

2024

Retrieval Metrics Demystified: From BM25 Baselines to EM@5 & Answer F1

5 minute read

Published:

“If a fact falls in a database and nobody retrieves it, does it make a sound?”
Retrieval‑Augmented Generation (RAG) lives or dies on that first hop—can the system put the right snippets in front of the language model?
In this post we peel back the buzzwords (BM25, EM@5, F1) and show how to turn them into levers you can actually pull.

Classical Planning 101: From STRIPS Blocks to Graphplan Magic

4 minute read

Published:

If you’ve ever written a to-do list—“get key → unlock door → leave house”
you’ve already built a plan. Classical planning turns that intuition into algorithms that guarantee the sequence really works.

2023

Math for AI Made Simple: The Linear-Algebra Lego Set Behind Every Model

7 minute read

Published:

If you can stack toy blocks, you already have the right intuition for the math that powers today’s AI.
This post unpacks the four shapes of numbers—scalars, vectors, matrices, and tensors—and the handful of moves we do with them.
No whiteboard proofs, no scary symbols—just pictures, stories, and runnable code snippets.

2021

Homomorphic Encryption (HE) Explained: A Beginner’s Guide to Secure AI on Encrypted Data

5 minute read

Published:

Imagine this: You send a message to a server. That message is completely encrypted—nobody can read it. But the server still knows whether your message is harmful or not. It didn’t decrypt it. It didn’t peek inside. It just… ran a program on the encrypted data. Sounds like magic? That’s Homomorphic Encryption (HE).