Articles for people who
ship the stack
Original rewrites on React, Node.js, TypeScript and AI — practical notes from the same engineering practice behind our operator software. Article bodies are in English.
Tagged: middleware
LangChain @dynamic_prompt for task-aware system instructions
Build one HR agent that swaps Leave, Benefits, and Admin system prompts from runtime context—while keeping authorization in application code.
887 wordsRead articleGate Agent Tools Per User with LangChain Wrap Middleware
One calculator agent, three access tiers: wrap-style middleware overrides the tool list from runtime user_type instead of cloning three agents.
944 wordsRead articleHardening a Python LangChain Agent with Seven Built-In Middlewares
Learn how LangChain 1.0 middleware adds summarization, call limits, retries, model fallback, PII redaction and human approval to a Gemini agent without touching its core logic.
2604 wordsRead articleSeven Beginner Node.js and Express Coding Tasks, Solved and Explained
Work through seven typical junior Node.js interview tasks, from Express routes and middleware to error handling, string reversal and duplicates, and learn to explain each one.
1640 wordsRead articleAuthentication vs Authorization: Where Each One Belongs in Your Code
Learn how authentication and authorization differ in implementation, HTTP status codes, and system architecture to prevent common security bugs.
1335 wordsRead articleBuilding Safe AI Agents with LangChain Guardrails and Middleware
Learn how deterministic and model-based guardrails work in LangChain to catch PII leaks, enforce business rules, and add human approval steps to AI agents.
3413 wordsRead article
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