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Design a basic message queue system

PremiumDistributed infrastructureHard

  • Message queue
  • Distributed systems
  • Asynchronous processing

Quick answer

This distributed infrastructure interview question asks you to design a basic message queue system. Aim for a design that keeps working across many machines and failures, then explain partitioning, replication, coordination and trade-offs. Interviewers want to see how you reason about failures, consistency and scale.

The problem

Design a basic distributed message queue system similar to RabbitMQ, Kafka, or SQS that enables asynchronous communication between services.

What must a basic message queue system do?

  • Producers can publish messages to a queue or topic.
  • Consumers can subscribe to queues or topics and process messages.
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How well must it do it?

  • The system should be highly available and fault tolerant.
  • Message publishing and consumption should have low latency.
4 more requirementsUnlock to see all

What scale should you design for?

Use these numbers in your estimates.

The scale numbers unlock with this questionUnlock

Key concepts

  • Message queue
  • Distributed systems
  • Asynchronous processing
  • Fault tolerance
  • Consumer scaling
  • Message persistence

How you’ll practise

6 short steps · save and come back any time
  1. Requirements
  2. Estimate
  3. Data model and API
  4. Partitioning and replication
  5. Consistency and failures
  6. Wrap-up

Lala, personalized to you, gives a hint when you ask and reviews your design when you are ready.

What do interviewers look for?

In any distributed infrastructure design round.

  • States the consistency and availability guarantees up front
  • Explains partitioning and replication choices
  • Describes how nodes agree and recover after failures
  • Handles network partitions and slow nodes
  • Plans for adding and removing capacity safely
  • Names the trade-offs instead of hiding them

Questions people ask about this interview question

Which design type is this question?
It is a distributed infrastructure question. You design a basic message queue system and explain your choices the way you would in an interview.
Is this question asked at entry level?
It is marked Hard. It suits engineers preparing for senior interviews, where you are expected to drive the discussion and go deep on trade-offs.
What should I cover first?
Start with the guarantees the system must give and the failures it must survive. Agree on scope with the interviewer before you design anything.
Can I practise it for free?
It is a premium question. Sign up and unlock it once for 10 credits; it then stays unlocked. When you finish, Lala, your personalized AI mentor, can review your design for 30 credits.

Related questions

Updated · Written by the SevyDevy team

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