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Design a container orchestrator like kubernetes

PremiumCloud infrastructureHard

  • Kubernetes
  • Control loops
  • Pod scheduling

Quick answer

This cloud infrastructure interview question asks you to design a container orchestrator like kubernetes. Aim for a design that runs reliably and securely in the cloud at a sensible cost, then explain the services, regions, deployment and trade-offs. Interviewers want to see how you balance reliability, security and cost.

The problem

Design a container orchestrator like Kubernetes: users declare which containers they want, and the system places them on a cluster of machines and keeps them running. The hard parts are scheduling thousands of pods well, healing failures without humans and keeping one consistent source of truth.

A user submits desired state, for example a deployment of 20 replicas of an image, each requesting 500m CPU and 1 GiB of memory. The orchestrator stores it, schedules pods onto nodes with room, starts containers through an agent on each node, and keeps comparing actual state with desired state.

What must a container orchestrator like kubernetes do?

  • Declarative API: Create, update, delete and watch objects such as pods, deployments, services and nodes; clients state the result they want, not the steps.
  • Scheduling: Place each pending pod on a node that fits its CPU and memory requests, node selectors, affinity rules and taints, and spread replicas across zones.
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How well must it do it?

  • Consistent state: One strongly consistent source of truth; concurrent updates use optimistic concurrency so no write silently overwrites another.
  • Control plane failure: Losing one control-plane machine or zone does not stop the cluster, and running pods keep serving even if the whole control plane is down.
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What scale should you design for?

Use these numbers in your estimates.

The scale numbers unlock with this questionUnlock

Key concepts

  • Kubernetes
  • Control loops
  • Pod scheduling
  • Etcd
  • Raft
  • Rolling updates

How you’ll practise

6 short steps · save and come back any time
  1. Requirements
  2. Environments and topology
  3. Deployment pipeline
  4. Reliability and disaster recovery
  5. Observability and cost
  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 cloud infrastructure design round.

  • Clarifies availability, security and cost targets
  • Chooses managed services with reasons
  • Plans regions, zones and failover
  • Covers identity, secrets and network boundaries
  • Explains deployment, rollback and observability
  • Keeps an eye on cost as usage grows

Questions people ask about this interview question

Which design type is this question?
It is a cloud infrastructure question. You design a container orchestrator like kubernetes 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 workloads, the availability target and the security and cost limits. 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.

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Updated · Written by the SevyDevy team

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