Technical screening questions
Ask for one example per question and listen for specifics.
- How do partitions and consumer groups work? A good answer: Parallelism and ordering within a partition.
- How do you choose a partition count? A good answer: Throughput, consumers and future growth.
- How do you handle consumer lag? A good answer: Scale consumers, find slow processing and tune fetch.
- What delivery guarantees does Kafka offer? A good answer: At-most-once, at-least-once and exactly-once with transactions.
- How do you evolve a message schema? A good answer: Schema Registry and compatibility rules.
Quick screening questions
Use these when you have only a few minutes.
- How big were your clusters and throughput?
- How do you handle consumer lag?
- Describe a data loss or ordering issue you resolved.
What separates the levels
Match the level to the requirement before you submit.
- Junior: writes producers and consumers.
- Mid: operates and tunes.
- Senior: designs the streaming platform.
Red flags
Any of these is a reason to probe further.
- Only produced and consumed with a library.
- Cannot explain ordering.
- No operations experience for an operator role.
Tools you should hear mentioned
A Kafka engineer with real experience usually names several of these without prompting.
- Apache Kafka
- Kafka Connect
- Kafka Streams
- Schema Registry
- Monitoring tools
- Java or Python
Run the call well
Ask for the last project first, then dig into the second or third question. Take notes on versions, team size and outcomes, and record them with the submission so the vendor’s later technical interview does not surprise you.
Frequently asked questions
How long should a Kafka engineer screening call take?
Fifteen to twenty minutes is enough to cover the project, three technical questions and availability, rate and work authorization.
Do recruiters need to know the technology?
Working vocabulary is enough. Use the sourcing guide for the role and listen for specifics instead of judging technical depth yourself.