Kafka # Event Flow Diagram

 Here is a clean, easy-to-understand, interview-ready Kafka Event Flow Diagram (ASCII text).

You can directly use this in interviews for Microservices, Java, Kafka, Event-Driven Architecture.

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⭐ Kafka Event Flow Diagram (Microservices Architecture)

                         ┌───────────────────────────┐
                         │        PRODUCER           │
                         │  (Order Service, etc.)    │
                         └─────────────▲─────────────┘
                                       │ 1. Publish Event
                                       │
                                       ▼
                         ┌───────────────────────────┐
                         │        KAFKA TOPIC        │
                         │    "ORDER_PLACED"         │
                         └─────────────▲─────────────┘
                                       │
                    ┌──────────────────┼──────────────────┐
                    │                  │                  │
                    ▼                  ▼                  ▼
           ┌────────────────┐  ┌────────────────┐  ┌────────────────┐
           │  CONSUMER      │  │  CONSUMER      │  │  CONSUMER      │
           │ Inventory Svc  │  │ Payment Svc    │  │ Notification   │
           └───────▲────────┘  └──────▲─────────┘  └──────▲────────┘
                   │                   │                    │
          2. Process event     2. Process event     2. Process event
                   │                   │                    │
                   ▼                   ▼                    ▼
       ┌──────────────────┐  ┌──────────────────┐  ┌──────────────────┐
       │ Update Stock DB  │  │ Initiate Payment │  │ Send SMS/Email   │
       └──────────────────┘  └──────────────────┘  └──────────────────┘

─────────────────────────────────────────────────────────────────────────────
                           EVENT CHAIN (Downstream)
─────────────────────────────────────────────────────────────────────────────

Payment Svc publishes → "PAYMENT_SUCCESS" topic

                         ┌───────────────────────────┐
                         │  PRODUCER (Payment Svc)   │
                         └─────────────▲─────────────┘
                                       │
                                       ▼
                         ┌───────────────────────────┐
                         │   KAFKA TOPIC             │
                         │  "PAYMENT_SUCCESS"        │
                         └─────────────▲─────────────┘
                                       │
             ┌─────────────────────────┼────────────────────────────┐
             │                         │                            │
             ▼                         ▼                            ▼
   ┌────────────────┐       ┌────────────────┐            ┌────────────────┐
   │ Order Service  │       │ Shipping Svc   │            │ Notification   │
   │ Update status  │       │ Create delivery│            │ Send updates   │
   └────────────────┘       └────────────────┘            └────────────────┘

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⭐ Kafka Event Flow (Step-by-Step Explanation)

1️⃣ Producer sends event

Order Service → publishes ORDER_PLACED to Kafka.

2️⃣ Kafka stores event

Kafka Topic partitions store the event for consumers.

3️⃣ Consumer Groups listen

Multiple services consume the same event independently:

• Inventory

• Payment

• Notification

4️⃣ Each service processes event

Inventory reduces stock,
Payment starts transaction,
Notification sends updates.

5️⃣ Downstream events

Payment publishes PAYMENT_SUCCESS,
which triggers Order update + Shipping.

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⭐ Want More Kafka Diagrams?

I can give you:

✅ Kafka + Microservices Full Architecture
✅ Kafka Partition + Offset Diagram
✅ Kafka Consumer Group Diagram
✅ Kafka Stream Processing Diagram
✅ Real-world Banking Kafka Flow

Just tell me!