Top 50 AWS Cloud Platform Engineering Questions & Answers

Focused on Docker, Kubernetes, GitOps, ArgoCD, Terraform, Ansible, Prometheus, Grafana, Elasticsearch, and related cloud-native tools.

AWS Cloud Platform Fundamentals

1. What are the key pillars of the AWS Well-Architected Framework?
   • Answer: Operational excellence, security, reliability, performance efficiency, and cost optimization. These guide the design, deployment, and management of AWS workloads for scalability, resilience, and security.
2. How does AWS implement Infrastructure as Code (IaC)?
   • Answer: AWS provides tools like CloudFormation and CDK, and supports third-party tools like Terraform and Ansible to define, provision, and manage cloud resources using code for repeatability and version control.
3. What is Amazon Elastic Kubernetes Service (EKS) and why use it?
   • Answer: EKS is AWS’s managed Kubernetes service, offering automated cluster management, security, and reliability for running containerized applications at scale.
4. How do you use Docker on AWS?
   • Answer: Deploy Docker containers on EC2, ECS (Elastic Container Service), and EKS. AWS also offers Elastic Container Registry (ECR) for image storage and management.
5. What is GitOps and how does it benefit AWS deployments?
   • Answer: GitOps is a declarative model where Git serves as the source of truth for infrastructure/app deployments. Changes to Git repositories trigger automated deployments via tools like ArgoCD, enabling safer, auditable, and traceable changes.

DevOps, CI/CD & Automation

1. How do you automate container deployment pipelines on AWS?
   • Answer: Use CodePipeline and CodeBuild for CI/CD, integrate with ECR, EKS/ECS, and tools like ArgoCD for declarative deployments. Infrastructure can be managed by Terraform or AWS CloudFormation.
2. What is ArgoCD and how is it used with AWS EKS?
   • Answer: ArgoCD is a continuous delivery tool for Kubernetes, ensuring cluster state matches Git-defined manifests. On EKS, ArgoCD syncs application states directly with infrastructure code in Git repositories for repeatable, scalable deployments.
3. What is the preferred approach to Kubernetes manifest versioning in GitOps?
   • Answer: Store manifests in Git repositories. Tag/branch for environment separation, use pull/merge requests for code review, and employ ApplicationSets in ArgoCD for multi-cluster or multi-env deployment management.
4. How can Terraform be used to manage AWS resources for Kubernetes platforms?
   • Answer: Terraform modules can provision VPCs, EKS clusters, IAM roles, security policies, and integrate addons or nodegroups for scalable, reproducible environments.
5. How is Ansible used in AWS cloud engineering?
   • Answer: Ansible automates provisioning, security patching, config management, and application deployments across AWS resources, EC2 hosts, and even EKS/ECS environments.

Containers & Orchestration

1. What are best practices for Docker image creation for AWS deployments?
   • Answer: Use minimal base images, multi-stage builds, explicit version pinning, non-root users, and scan for vulnerabilities.
2. Explain how ECR integrates with Kubernetes and CI/CD.
   • Answer: ECR serves container images to EKS or ECS. CI/CD pipelines push new images, triggering deployments or ArgoCD sync.
3. What are the key components of a Kubernetes cluster on AWS?
   • Answer: Control Plane (managed by AWS in EKS), worker nodes (EC2 or Fargate), networking (VPC, subnets, security groups), IAM roles, and storage (EBS/EFS).
4. How do you implement resource limits and quotas in EKS?
   • Answer: Define Kubernetes ResourceQuota and LimitRange objects in namespaces; control node sizes/types via Terraform or eksctl.
5. What is a Kubernetes Operator and its use case on AWS?
   • Answer: Operators are custom controllers automating complex app management (e.g., RDS, S3, Elasticsearch clusters) and integrating with AWS services for lifecycle automation.

Monitoring, Observability & Logging

1. How do you monitor AWS EKS using Prometheus and Grafana?
   • Answer: Deploy Prometheus for collecting Kubernetes metrics. Use Grafana, connected to Prometheus, for dashboards. Metric data can be exported to AWS Managed Prometheus/Grafana services.
2. What are Prometheus exporters and their role in cloud-native monitoring?
   • Answer: Exporters collect metrics from various sources (EC2, EBS, Kubernetes, etc.) and expose them in Prometheus format.
3. How would you aggregate and visualize AWS logs in Elasticsearch?
   • Answer: Use Fluentd/Fluent Bit/Logstash agents in EKS or Lambda for log forwarding from containers, ALB, S3, or CloudWatch to Elasticsearch/OpenSearch, visualized in Kibana/Dashboards.
4. How do you implement alerting with Prometheus on AWS?
   • Answer: Use Alertmanager with Prometheus to send notifications (SNS, email, Slack) based on metric thresholds.
5. What is the benefit of centralized logging for containerized workloads?
   • Answer: Centralization enables unified search, traceability, compliance, and troubleshooting across distributed, ephemeral workloads.

Security & Best Practices

1. How can IAM Roles for Service Accounts (IRSA) improve Kubernetes security on AWS?
   • Answer: Assign least-privilege IAM permissions directly to Kubernetes Service Accounts for secure AWS resource access from pods.
2. Explain securing secrets in Kubernetes on AWS.
   • Answer: Use Kubernetes Secrets stored in encrypted etcd, integrate with AWS Secrets Manager/Parameter Store, and restrict access via RBAC.
3. How do you automate security compliance for Kubernetes workloads?
   • Answer: Use tools like kube-bench, kube-hunter, OPA/Gatekeeper, and integrate with CI/CD for regular scanning and enforcing policies.
4. What is Network Policy in Kubernetes and how is it applied in AWS EKS?
   • Answer: Network Policies control pod communication. In AWS, use Calico or native CNI plugins to enforce traffic rules between pods/namespaces.
5. How is TLS termination and HTTPS enforced on Kubernetes apps in AWS?
   • Answer: Use AWS ALB/NLB ingress controllers with ACM certificates or cert-manager for automated certificate management and HTTPS enforcement.

GitOps, ArgoCD & Automation

1. What key features distinguish ArgoCD from other CD tools?
   • Answer: Native Kubernetes integration, declarative config, automatic sync, multi-cluster management, rollback capabilities, and robust RBAC.
2. Describe a GitOps workflow using ArgoCD and Terraform on AWS.
   • Answer: Terraform provisions cluster and AWS infrastructure. Kubernetes manifests are stored in Git, with ArgoCD syncing to EKS. Infra and application changes are tracked, auditable, and automated.
3. How do you manage secrets and sensitive data in GitOps processes?
   • Answer: Never store secrets unencrypted in Git. Use SOPS, Sealed Secrets, AWS Secrets Manager, or encrypted variables in manifests.
4. How does ArgoCD detect and remediate drift in your application state?
   • Answer: ArgoCD continuously monitors actual vs. desired state (from Git), highlighting drift and optionally auto-syncing for remediation.
5. What is ApplicationSet in ArgoCD and its advantage for AWS workloads?
   • Answer: ApplicationSets automate creating multiple ArgoCD App objects, supporting multi-cluster, multi-region or SaaS-style deployments from templates.

Terraform & Advanced Infrastructure

1. How do you structure Terraform modules for AWS platform engineering?
   • Answer: Use reusable modules with clear inputs/outputs. Separate account/core infra (VPC, EKS), networking, security, and app modules.
2. Describe state management best practices in Terraform on AWS.
   • Answer: Store state remotely in S3 with versioning and DynamoDB for locking, secure with encryption.
3. How do you perform zero-downtime updates of EKS clusters using Terraform?
   • Answer: Use rolling node group upgrades, blue-green deployments, and proper resource dependencies.
4. How do workspaces in Terraform assist with multi-environment AWS deployments?
   • Answer: Workspaces allow parallel, isolated state files for dev, staging, prod, with environment-specific variables.
5. What is Terragrunt and how does it augment Terraform usage on AWS?
   • Answer: Terragrunt provides DRY patterns, config inheritance, and automation for managing complex multi-account/multi-env infrastructures.

Kubernetes Operations & Day-2 Management

1. How do you automate day-2 Kubernetes operations on AWS?
   • Answer: Use Kubectl runbooks, Helm scripts, operators, and integrate with tools like Ansible or AWS SSM for patching/lifecycle.
2. How to achieve disaster recovery and high availability for EKS workloads?
   • Answer: Multi-AZ node groups, cross-region backups, frequent manifest/volume backups, pilot-light or active-active DR patterns.
3. How do you observe and remediate pod-level failures in EKS?
   • Answer: Monitor with Prometheus, alert with Alertmanager, and automate remediation (e.g., restart pods, trigger rollout) using Kubernetes and AWS Lambda.
4. Describe blue-green and canary deployments in Kubernetes on AWS.
   • Answer: Use ingress rules, labels, and deployment strategies to incrementally route traffic in EKS, automate with Argo Rollouts for fine-grained control.
5. How can you scale Kubernetes clusters automatically in AWS?
   • Answer: Enable Cluster Autoscaler for node management, use HPA and VPA for pod resource scaling, tie metrics with Prometheus for precision.

Advanced Platform Engineering, Troubleshooting & Best Practices

1. Explain a troubleshooting process for network latency in EKS.
   • Answer: Use kubectl to inspect pod/node states, monitor network metrics in Grafana, use VPC Flow Logs, and trace traffic using AWS X-Ray or third-party tools.
2. What are Kubernetes taints and tolerations and why use them?
   • Answer: Control which pods run on which nodes, ensuring isolation (e.g., running GPU workloads only on GPU nodes).
3. How do you backup and restore Kubernetes resources and persistent data in AWS?
   • Answer: Use Velero for manifest/volume backup to S3, regular EBS snapshots, and database backup tools.
4. What is a Service Mesh and its use in AWS EKS?
   • Answer: Service Mesh (e.g., Istio, AWS App Mesh) provides observability, traffic management, and security between microservices running in EKS.
5. How do you manage configuration drift in AWS infrastructure?
   • Answer: Use IaC tools (Terraform, Ansible), enforce drift detection (e.g., Terraform plan), and automate drift remediation workflows.

Real-world Scenarios, Tips & Best Practices

1. How do you efficiently roll out security patches to running containers?
   • Answer: Use CI pipelines to rebuild and redeploy patched images, automate with Kured for node restarts, or manage rolling updates in EKS/EC2.
2. What is the best way to aggregate app, container, and audit logs from AWS accounts?
   • Answer: Centralize in CloudWatch Logs, forward to Elasticsearch/OpenSearch or third-party SIEMs, and use dashboards for filtering/searching.
3. How do you implement custom alerts and dashboards for AWS infrastructure?
   • Answer: Use Prometheus for metrics collection, Alertmanager for custom alerting, and design Grafana dashboards with RBAC for stakeholder access.
4. How do you structure Git repositories for scalable GitOps on AWS?
   • Answer: Use mono repos or micro-repos per environment/app as needed; separate application code, infrastructure code, and ArgoCD application definitions.
5. What practices help you stay current with AWS cloud-native advancements?
   • Answer: Follow AWS release notes, official blogs, open-source repo updates, attend webinars/conferences, and participate in the cloud-native community.