NDNikhil Dhawaninreact-expo.hashnode.dev·Jul 9 · 7 min readWhat Is RAG? A Simple Guide (and Why It Still Fails Sometimes)A normal LLM answers from what it learned in training. RAG (Retrieval-Augmented Generation) first fetches relevant information, then asks the model to answer using that information. This usually impro00
NDNikhil Dhawaninreact-expo.hashnode.dev·Jun 30 · 11 min readHow ChatGPT Understands Your Questions? What is an LLM? Explained Like You're 5 A friendly, no-jargon tour through ChatGPT, tokens, and Transformers, with simple diagrams you can actually understand. TL;DR — An LLM is a giant pattern-match00
NDNikhil Dhawaninreact-expo.hashnode.dev·May 26 · 11 min readHow Instagram Stores Reels, Photos, and Drafts Behind the ScenesImagine recording a Reel during a train ride with unstable internet. You add music, trim clips, apply filters, write a caption, and then suddenly your network disappears. Instead of losing everything,00
NDNikhil Dhawaninreact-expo.hashnode.dev·May 26 · 10 min readHow WhatsApp Works Without Internet: Offline Messaging and Sync ExplainedImagine this situation. You are traveling on a flight and switch your phone to airplane mode. While offline, you open WhatsApp and type: “I’ll land in two hours.” You tap send. Surprisingly, the messa00
NDNikhil Dhawaninreact-expo.hashnode.dev·May 21 · 12 min readExpo Router vs React Navigation — Which One Should You Use in 2026?Mobile apps are no longer just a collection of screens. Modern React Native applications contain: Authentication systems Nested dashboards Deep linking Tabs inside stacks Shared layouts Protecte00