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Cost Optimization at Scale Questions

Addresses cost conscious design and operational practices for systems operating at large scale and high volume. Candidates should discuss measuring and improving unit economics such as cost per request or cost per customer, multi tier storage strategies and lifecycle management, caching, batching and request consolidation to reduce resource use, data and model compression, optimizing network and input output patterns, and minimizing egress and transfer charges. Senior discussions include product level trade offs, prioritization of cost reductions versus feature velocity, instrumentation and observability for ongoing cost measurement, automation and runbook approaches to enforce cost controls, and organizational practices to continuously identify, quantify, and implement savings without compromising critical service level objectives. The topic emphasizes measurement, benchmarking, risk assessment, and communicating expected savings and operational impacts to stakeholders.

MediumTechnical
49 practiced
You maintain a distributed ingestion pipeline sending data to an external analytics vendor. Network costs are high and throughput is suboptimal. Propose optimizations around chunking/aggregation sizes, compression codecs, parallelism degree, backpressure mechanisms, and protocol selection (HTTP, gRPC, streaming). Explain trade-offs between CPU cost for compression and network egress savings under a 1-hour end-to-end SLA.
HardTechnical
51 practiced
You discover a product feature costing $X/month but delivering little measurable user value. How would you prepare and run a conversation with a skeptical product manager to recommend disabling or deprioritizing the feature? Outline the data, experiments, risk mitigation, and communication plan you would bring to the meeting.
EasyTechnical
51 practiced
Given a table 'storage_objects' with columns (object_id text, size_bytes bigint, storage_class text, created_at timestamp, last_access_at timestamp), write a SQL query that returns (1) total storage per storage_class in GB and (2) the 10 oldest objects in 'STANDARD' class with their sizes and days-since-last-access. Show assumptions about timezone and rounding.
EasyTechnical
48 practiced
Compare reserved instances, savings plans, and committed use discounts across cloud providers. Discuss mechanics (commit term, flexibility across instance types), how to evaluate utilization risk, and how to decide what percentage of capacity to commit for a steady-state service.
EasyTechnical
41 practiced
Explain Kubernetes Horizontal Pod Autoscaler (HPA) vs Vertical Pod Autoscaler (VPA) vs Cluster Autoscaler. For each, describe how it impacts cost, what workloads it suits, and one operational risk when relying on it for cost optimization.

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