System Desgin
Custom AI Agent & Function-Calling Framework with TypeScript
Hook: A customer‑support bot that promised “instant answers” stalled at the third user request, spitting out “I’m sorry, I don’t understand.” The failure traced…
// category archive
System Desgin
18 articles
System Desgin
Persistent Memory & Context for JavaScript Conversational AI
TL;DR – Stateless chat models forget most of the conversation after a handful of turns. – Adding a persistence layer (Redis, PostgreSQL JSONB, or…
System Desgin
Cost Optimization for OpenAI Assistants API in Node.js
TL;DR – Quick Takeaways Keep Assistant threads short when possible; long‑lived threads inflate token counts. Cache recurring prompts and reuse completions to cut per‑call…
System Desgin
Vercel AI SDK vs LangChain.js: React AI Agent Comparison
TL;DR – Vercel AI SDK gives you a lean, edge‑first experience; launch a streaming chat UI in minutes. – LangChain.js shines when you need…
System Desgin
Secure API Keys & Prompts in Client‑Side JS AI Agents
TL;DR – Never embed production API keys directly in browser‑side JavaScript. – Use a backend proxy or server‑less function to shield credentials. – Add…
System Desgin
Local Document Q&A Agent with LlamaIndex.js & Next.js
TL;DR – Local RAG avoids data leakage and cuts per‑query costs. – Next.js 14’s App Router pairs nicely with LlamaIndex.js for end‑to‑end pipelines. – Choose…
System Desgin
Orchestrate Multi‑Step LLM Workflows with Node.js & CrewAI
💡 Pro Tip: If you ever watched an LLM “hallucinate” in a production ticket‑routing system, you know the pain of hand‑off failures. The story…
System Desgin
Debugging LLM Agent Hallucinations in JavaScript Apps
⚡ Opening Hook When a shopping‑cart bot on nileshblog.tech suggested a “premium banana‑infused Bluetooth speaker” to a customer, the order blew up the checkout pipeline.…
System Desgin
Implement AI Agents with LangChain.js – Beginner Guide
TL;DR – LangChain.js lets you stitch LLMs, tools, and memory into a single runnable agent. – You only need Node ≥ 18, an OpenAI API key,…
System Desgin
AI Code Reviewer in GitHub Actions: 2026 Guide
TL;DR – Native GitHub CodeQL misses semantic bugs that LLMs can spot. – Choose between local LLM inference and managed API with a decision…
Backend Dev
From PR to Production: How Kubernetes Deployments Actually Work (Single Service + Microservices in the Real World)
Most developers know how to write code. Fewer understand what actually happens after they click “Merge Pull Request.” And even fewer truly understand what…
Backend Dev
Why Your Node.js App Is Fast Locally but Slow in Production
A senior engineer’s deep dive into performance illusions, real bottlenecks, and hard-earned lessons If you’ve shipped a Node.js service to production, you’ve almost certainly…
Backend Dev
Idempotency Explained: How to Design Safe APIs That Don’t Break in Production
Idempotency is one of those topics that looks simple on paper and brutal in production. Most engineers understand the definition. Fewer understand the failure…
Backend Dev
Sprite Sheets in Node.js: How Video Platforms Show Fast Hover Previews Without Loading Hundreds of Images
Modern users don’t think in milliseconds — they think in feel. If a UI feels slow, it’s broken. And one of the most obvious…
Backend Dev
Stateless vs Stateful Services (With Real Examples)
If you’ve worked on backend systems long enough, you’ve probably heard this advice: “Make your services stateless.” It sounds simple. It sounds correct. And…
Backend Dev
Bloom Filter in Express.js (With Real Example and Dry Run Explained)
🧠 What is a Bloom Filter? A Bloom Filter is a probabilistic data structure used to test whether an element might be present in…
Backend Dev
Designing a Scalable URL Shortener: Snowflake IDs, Base62 Encoding, and Microservices
URL shorteners like Bit.ly or TinyURL are deceptively simple: take a long URL, generate a short one, and redirect. But when you want to…
Backend Dev
Designing a High-Concurrency Flash Sale Stock & Inventory Reservation System with Node.js, Redis, Lua, and MongoDB
Designing a High-Concurrency Flash Sale Stock & Inventory Reservation System with Node.js, Redis, Lua, and MongoDB