Load Balancing and Horizontal Scaling Questions

Covers principles and mechanisms for distributing traffic and scaling services horizontally. Includes load balancing algorithms such as round robin, least connections, and consistent hashing; health checks, connection draining, and sticky sessions; and session management strategies for stateless and stateful services. Explains when to scale horizontally versus vertically, capacity planning, and trade offs of each approach. Also includes infrastructure level autoscaling concepts such as auto scaling groups, launch templates, target tracking and step scaling policies, and how load balancers and autoscaling interact to absorb traffic spikes. Reviews different load balancer types and selection criteria, integration with service discovery, and operational concerns for maintaining availability and performance at scale.

MediumTechnical

0 practiced

Design an ingress/load balancing architecture for a Kubernetes cluster that must support 100k RPS and long-lived WebSocket connections. Include components (external LB type, ingress controller, service type, node sizing), connection draining strategy for rolling nodes, and how you would test at scale.

HardTechnical

0 practiced

Your organization wants to reduce cost of load balancing and autoscaling while keeping SLOs. Propose three concrete strategies (e.g., using spot instances, right-sizing instances, using fewer larger instances, request batching, API gateway caching). For each strategy, list risks and mitigations.

HardTechnical

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Design observability for your load balancers and autoscalers. Specify the metrics, logs, and distributed traces you would collect (examples: active connections, target registration events, target health state changes, scale actions, provisioning durations) and how you would tag and aggregate them for alerting and capacity planning.

HardTechnical

0 practiced

Compare TLS termination options: terminate at the external load balancer, terminate at an edge proxy and re-encrypt to backend, or terminate at the backend. Discuss trade-offs for performance, end-to-end security (including mTLS), certificate management complexity, and observability.

EasyTechnical

0 practiced

Explain what sticky sessions (session affinity) are and list three alternatives for session management suitable for horizontally scaled web services. For each alternative, describe trade-offs in latency, consistency, and operational complexity.

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