High Kafka Question 193 of 226

What is change data capture, and when is Debezium a better producer than your app?

Java Specialist · Speak this in 60–90 seconds · Faridabad & Delhi NCR

PICTURE THIS: DATABASE INDEX

Without indexScan every row
With indexJump to keys
CostWrites slower

Simple meaning

CDC reads the database transaction log and emits row changes as Kafka events, so you cannot forget to publish after a commit.

1

WHY — Kafka instead of guessing?

Why interviewers care about Kafka:

Kafka questions separate people

who only read docs from people who shipped.

Keep it short, concrete,

and tied to Backend work.

Stay structured

Name the idea, why it exists, then one short example.

Close cleanly

End with when you use it and one common pitfall.

2

STEPS — What happens step by step?

Before you speak the answer, walk the interviewer through these steps:

  1. 1
    CDC reads the database

    transaction log and emits row changes as Kafka events, so you cannot forget to publish after a commit.

  2. 2
    It is ideal when

    many producers already write SQL and you need a reliable stream.

  3. 3
    You still need a

    schema strategy and you must handle snapshots, deletes, and tombstones.

  4. 4
    Give an example

    One tiny concrete case you can say aloud.

  5. 5
    Common mistake

    What juniors usually get wrong.

  6. 6
    Close

    When you pick this over the alternative.

3

EXAMPLE — See it in action

Here's a short line you can speak, broken into clear beats:

Say this line
“It is ideal when many producers already write SQL and you need a reliable stream”
Break into beats
Itisidealwhenmanyproducers
Speaking order
2987408337471632900

Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

Key takeaway

CDC reads the database transaction log and emits row changes as Kafka events, so you cannot forget to publish after a commit. It is ideal when many producers already write SQL and you need a reliable stream.

Chat with us