System Design 103 - Stateless vs Stateful Systems — Explained Using Banking Systems

In this video, we break down one of the most fundamental concepts in system design — stateless vs stateful systems. We start with simple intuition and real-world analogies, and then go deeper into how modern systems are actually built. Using examples from Instagram and real-world banking systems, we explore how scalability and consistency are balanced in practice. You’ll also learn: How backend systems handle stateful transactions What happens when transactions fail How duplicate transactions are avoided using idempotency Why banking systems rely on a source of truth ledger Watch the previous video (Start here): System Design 102 - How to choose a database for your system? https://youtu.be/Emzg4rcSHZs?si=_k9yCTA4UBA34p_U Topics Covered: Stateless systems, Stateful systems, System Design basics, Banking architecture, Transactions, Idempotency, Distributed systems Why this matters If you’re trying to understand how real systems work under the hood, this is a concept you need to get right. 🔔 Follow the series This is part of my System Design series, where we go from fundamentals → real-world system design step by step. #systemdesign #distributedsystems #backendengineering #scalablesystems #techexplained