Design and explain infra, K8s, routing, and fleet

Q: Design and explain infra, K8s, routing, and fleet

This is a System Design interview question from Lambda for Software Engineer roles. View the full question and solution on PracHub.

Q: How do I approach System Design interview questions?

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Question

System Design and Operations Deep-Dive

Context: You are interviewing for a Software Engineer role with a focus on system design and engineering. Provide concise, design-oriented answers with justifications and operational guardrails.

1) Infrastructure as Code (IaC) and CI/CD for Bare Metal and Kubernetes

Describe a reference design to provision and update bare-metal servers and Kubernetes clusters via CI/CD. Address:

Secrets management (bootstrapping, in-cluster, and at-rest)
Idempotency and safe rollouts
Drift detection and policy enforcement

2) Kubernetes Control Plane and Workload Management

Explain Kubernetes’ reconciliation loop and how controllers converge desired vs. observed state.
Outline strategies for workload management:
1. Scheduling primitives (affinity/anti-affinity, taints/tolerations, topology spread)
2. Resource requests/limits and LimitRanges
3. ResourceQuotas and fair-share
4. Horizontal Pod Autoscaler (HPA) and Vertical Pod Autoscaler (VPA)
5. Cluster Autoscaler (CA)
6. Multi-tenancy models and recommended guardrails

3) Edge Firmware/Fleet Management

Design and operate a solution for edge devices that supports:

Secure OTA updates (signing, A/B, deltas)
Staged rollouts and canarying
Automatic rollback and break-glass procedures
Device identity, health telemetry, and fleet observability

4) IP Routing and Troubleshooting

Explain routing tables and longest-prefix match. Contrast static vs. dynamic routing.
Troubleshoot blackholes and asymmetric routing; list diagnostic steps and mitigations.

5) Homelab

Share a practical homelab setup that demonstrates your skills across automation, Kubernetes, networking, observability, and security. Explain what it proves about your capabilities.