System Design: Chat System (WhatsApp / Messenger Scale)
A chat system is a perennial system design interview question. It requires you to reason about real-time communication, persistent storage, […]
A chat system is a perennial system design interview question. It requires you to reason about real-time communication, persistent storage, […]
Designing a social media feed is one of the most nuanced system design problems you’ll encounter in interviews. It looks
The bias-variance tradeoff is one of the first concepts asked in any machine learning interview. It underpins model selection, regularization,
Designing a URL shortener is one of the most common system design interview questions, especially at the intern and new
“Which database would you use?” is one of the most common follow-up questions in system design interviews. Many candidates default
Every system you design needs an API. In system design interviews, choosing the right API style — and explaining why
Gradient descent is the engine behind nearly every machine learning model trained today. If you are interviewing for an ML
A load balancer sits in front of a pool of servers and distributes incoming requests across them. It is one
Message queues decouple the components of a distributed system so that producers and consumers can operate independently. They appear in
Caching is the single highest-leverage optimization in most system designs. Before you reach for database sharding or complex infrastructure, a
Database sharding is a core scaling technique you’ll need to explain in nearly any large-scale system design interview. The question
The CAP theorem comes up in almost every senior-level system design interview. Interviewers ask it because it forces you to
Consistent hashing is one of the most commonly asked system design concepts at big tech companies. You will almost certainly
Twitch Interview Guide 2026: Live Streaming Infrastructure, Real-Time Chat, and Creator Platform Engineering Twitch (Amazon subsidiary) is the world’s leading
Shopify Interview Guide 2026: E-Commerce Infrastructure, Ruby/Rails Engineering, and Multi-Tenant Scale Shopify powers 10%+ of US e-commerce with 1.7M+ merchants.