RSRobin Singhinunknowntoplay.hashnode.dev·Apr 10 · 13 min readI Built a RAG App That Chats With Any PDF — Here's HowI Built a RAG App That Chats With Any PDF — Here's How TL;DR: I built DocMind — a multimodal RAG (Retrieval-Augmented Generation) app that lets you upload any PDF, image, or document and ask questions about it in plain English. No API keys needed — i...00
RSRobin Singhinunknowntoplay.hashnode.dev·Apr 10 · 13 min readThe Node.js Event Loop — Finally Explained RightTL;DR: The event loop is how Node.js handles thousands of concurrent operations with a single thread. It's not magic — it's a loop with 6 phases, each processing a specific type of callback. This post breaks down every phase with diagrams, shows you ...00
RSRobin Singhinunknowntoplay.hashnode.dev·Apr 10 · 18 min readSystem Design: Real-Time Stock Trading Platform — From My Experience Building MstockTL;DR: I helped build Mstock, a stock trading platform handling 100K+ concurrent users during market hours. This post walks through the full system design — from WebSocket connections for live prices, to order matching, to the caching and database la...00
RSRobin Singhinunknowntoplay.hashnode.dev·Apr 10 · 13 min readHow Redis Caching Actually Works — A Visual Guide for Backend DevelopersHow Redis Caching Actually Works — A Visual Guide for Backend Developers TL;DR: Redis caching sits between your application and database, storing frequently accessed data in memory for sub-millisecond reads. This guide walks through cache-aside, writ...00