How Food Delivery Apps Like Swiggy & Zomato Stay Fast: The Magic of Apache Kafka

Imagine you ordered a burger from your favorite food delivery app like Zomato or Swiggy.

The app needs to:

• Accept your order
• Confirm payment
• Inform the restaurant
• Assign a delivery person
• Keep you updated

But...

When millions of people order food at the same time, how does the system stay fast, smooth, and reliable?

The secret weapon behind this magic is Apache Kafka.

In this blog, we'll learn:

• What Kafka is
• How it works
• Why it's super important
• What happens without it
• Real-world architecture examples!

Let’s dive in.

What is Kafka?

Kafka is an open-source distributed system used for:

• Sending (producing)
• Storing
• Receiving (consuming) data streams at scale — in real time.

You can think of Kafka as a giant message post office.

Apps send letters (messages) to Kafka, and different services pick up these letters and act on them.

Similar Apps Like Kafka

If you have heard of these, they are similar:

• RabbitMQ
• Amazon Kinesis
• Google Pub/Sub
• Redis Streams
• NATS

But Kafka is famous because it's ultra-scalable, durable, and lightning fast.

How Kafka Works (Simple Terms)

Basic Building Blocks:

In action:

1. Producer sends data to Kafka Topic.
2. Kafka stores the data safely across different Partitions.
3. Consumers read the data when they are ready.
4. Multiple services can consume the same data independently and in parallel.

Real-World Example: Food Delivery App Architecture with Kafka

Let’s take a real-life example of a Food Delivery App (like Swiggy/Zomato):

Step-by-Step Flow

1. User places an order via mobile/web app.
2. Kafka receives this order in a Topic called order-events.
3. Multiple services consume the same order at the same time:
   • Order Management Service → validates order.
   • Payment Service → processes payment.
   • Inventory Service → checks stock.
   • Restaurant Service → notifies the restaurant.
   • Delivery Service → assigns delivery person.
4. Delivery Service publishes an update in another Kafka Topic called delivery-events.
5. Notification Service reads delivery-events and sends SMS/push notifications to the user.

Architecture Diagram

Why Kafka is Super Important

Without Kafka:

• Every service would need to call APIs of other services directly.
• Huge load would crash the system during peak times.
• Delays, failures, and user frustration.

With Kafka:

• All services read events independently.
• The system becomes fast, scalable, and fault-tolerant.
• Millions of orders can be processed without chaos.

What If Kafka Was Not There?

Without Kafka:

• You would click "Order" and keep waiting.
• Payment might fail midway.
• Delivery assignment could be delayed.
• Notification could reach you very late or never.

In short — the whole system would break.

What about Zookeeper and KRaft?

Previously, Kafka needed a tool called Zookeeper to manage brokers and clusters.

But now, a new system called KRaft Mode (Kafka Raft Metadata mode) is replacing Zookeeper.

Benefits of KRaft:

• Simpler Kafka setup.
• Faster cluster operations.
• Less dependency on external systems.

(So modern Kafka deployments are moving towards KRaft Mode.)

Final Summary

Closing Thought

Kafka is like the heart of modern tech companies.

If you master Kafka, you can build systems that can handle millions of users — just like Netflix, Uber, Amazon, and Swiggy!

Hope this blog helped you move from zero to pro in Kafka understanding.

If you liked it, share it with your tech friends!