System Design Interview Hack!! Event Driven Kafka Logic!! #kafka #systemdesign #ai #learn #code #eda

Added: 2026-05-19

[00:00:00]In your next system design interview, if the interviewer says use Kafka here and your answer is yeah, we'll use an event-driven architecture, you're probably missing out on a very important design discussion. Because not all event-driven architectures are the same.

[00:00:12]There are four types, but two very commonly used. These are simple event notification and event carried state transfer. Here's the difference. In simple event notification, say an order is getting dispatched. So, our event will only contain an order ID. Every information related to that order will be fetched from the database or APIs via the consumer itself. Small message, cheap broker storage, but extra database call and thus more latency. Now, let's talk about event carried state transfer.

[00:00:38]Herein, the event has everything that you need. Order ID, customer name, customer address. All this is important to send the notification. So, your consumer does not have to make any extra query or calls. Now, you get lower latency, better decoupling, but your message is big. So, your broker cost and your storage is going to increase. In interviews, don't just say we'll use Kafka. Explain what kind of architecture you're choosing and why. This shows your system design maturity. Follow us for more such content.