Cloud Engineer Interview Questions
120 questions across 5 categories
Cloud-provider-specific depth — AWS, Azure, GCP — architecture, cost, and the platform-specific judgment calls each provider demands.
A blob was accidentally overwritten with bad data, not deleted. Both soft delete and versioning are enabled on the account. Why doesn't 'undelete' bring back the good version, and what actually will?
IntermediateAzureBlob Storage6 min
When does autoscaling actually save money compared to a well-chosen fixed capacity, and when can it end up costing more?
IntermediateAWSKubernetes6 min
Your architecture serves a large volume of data out to end users and other services, and data transfer/egress costs have become one of your largest line items. What architectural decisions actually reduce this?
AdvancedAWS8 min
Leadership wants to adopt a multi-cloud strategy specifically to reduce vendor lock-in and negotiate better pricing. What are the real cost trade-offs they might not be accounting for?
AdvancedAWSAzureGCP7 min
How would you decide what mix of Reserved Instances, Spot Instances, and On-Demand capacity to use across a workload with both steady baseline traffic and unpredictable spikes?
IntermediateAWS7 min
An audit finds most of your EC2 instances are running at under 15% average CPU utilization. How would you approach rightsizing them without risking a performance incident?
IntermediateAWS6 min
This month's cloud bill came in 3x higher than usual, with no corresponding increase in traffic or deliberate infrastructure change. How do you actually track down the cause?
IntermediateAWS8 min
How would you design the data layer differently for an active-active multi-region architecture versus an active-passive (failover) one?
ExpertAWS10 min
What's the actual difference between RPO and RTO, and how does each change depending on whether you're designing for multi-AZ or multi-region failover?
IntermediateAWS6 min
In a real system with dozens of services, how would you decide which specific ones actually need multi-region treatment versus which can safely stay single-region?
AdvancedAWS8 min
What's the actual difference between designing for high availability across Availability Zones versus across Regions, and when do you actually need multi-region instead of just multi-AZ?
AdvancedAWS8 min
A junior engineer asks why deploying across multiple Availability Zones in the same region isn't enough for 'true' disaster recovery. How would you explain the actual distinction between AZs and regions?
BeginnerAWS6 min
Finance is asking why the same infrastructure spend that used to be a predictable annual budget line is now a variable monthly cloud bill that's harder to forecast. How would you explain this shift?
BeginnerCloud Fundamentals5 min
A system that can scale from 10 to 1,000 servers is described as both 'scalable' and 'elastic' — are these actually the same property, and does the distinction matter practically?
BeginnerCloud Fundamentals5 min
What's the actual difference between IaaS, PaaS, and SaaS, and how would you decide which one is the right fit for a given workload?
BeginnerCloud6 min
How would you evaluate whether to move an existing IaaS-hosted application to a PaaS, given the migration cost involved?
IntermediateCloud7 min
A customer asks how their data stays isolated from other customers on the same physical cloud infrastructure. What's actually happening under the hood to make multi-tenancy safe?
IntermediateCloud Fundamentals6 min
What operational risks does heavy reliance on SaaS introduce that IaaS or PaaS generally don't — vendor lock-in and data portability included?
IntermediateCloud6 min
Where does serverless (e.g. AWS Lambda) actually fit on the IaaS/PaaS/SaaS spectrum — does it fit cleanly into any of those three categories at all?
IntermediateAWS6 min
A company got breached because an S3 bucket was publicly accessible, and leadership initially blamed AWS. Why is that framing wrong, and how does the shared responsibility model actually draw the line?
BeginnerAWS6 min
Leadership is nervous about 'vendor lock-in' and wants every architectural decision evaluated for portability across cloud providers. Is this concern well-founded, or often overstated?
IntermediateCloud Fundamentals6 min
What's actually different between Cloud Functions Gen 1 and Gen 2, beyond just a version number?
IntermediateGCPCloud Functions6 min
A function migrated from Gen 1 to Gen 2 started returning occasionally-wrong results under load — what changed, and how do you fix it?
ExpertGCPCloud Functions8 min
A Cloud Function's p99 latency is dominated by cold starts under bursty traffic — how would you mitigate this, and what's the actual cost trade-off?
IntermediateGCPCloud Functions7 min