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Complexity Analysis and Performance Modeling Questions

Analyze algorithmic and system complexity including time and space complexity in asymptotic terms and real world performance modeling. Candidates should be fluent with Big O, Big Theta, and Big Omega notation and common complexity classes, and able to reason about average case versus worst case and trade offs between different algorithmic approaches. Extend algorithmic analysis into system performance considerations: estimate execution time, memory usage, I O and network costs, cache behavior, instruction and cycle counts, and power or latency budgets. Include methods for profiling, benchmarking, modeling throughput and latency, and translating asymptotic complexity into practical performance expectations for real systems.

EasyTechnical
75 practiced
Describe the difference between Big O, Big Theta (Θ), and Big Omega (Ω) notation. For each notation, provide a simple example function and explain when each is most useful when analyzing algorithms commonly used in data pipelines (e.g., index lookup, sorting, joins).
MediumTechnical
73 practiced
Implement a Python function that processes a stream of integers and maintains the top-k largest elements seen so far using O(k) extra memory and O(log k) time per element. Provide code for insertion/update and retrieval of sorted top-k, and explain time and space complexity and how this approach fits a streaming ETL job.
HardTechnical
90 practiced
Create a 3-year capacity plan for an analytics platform ingesting 50 GB/day with hot retention of 2 years and cold retention of 3 additional years. Include storage growth projections, compression and compaction benefits, indexing costs, and query latency SLAs. Provide formulas, assumptions (compression ratio, growth rate), and how you would convert this into cloud or on-prem cost estimates.
MediumSystem Design
128 practiced
Design a throughput vs latency model for a streaming ingestion pipeline that must process 100k events/sec with 99th percentile processing latency < 500 ms. Cover message broker, consumers, and downstream DB: describe queuing models, how to size the number of consumers, how to compute required service rates, and heuristics for headroom to absorb spikes.
HardTechnical
106 practiced
Design a robust benchmarking methodology to compare two distributed ETL frameworks in a public cloud where noisy neighbors and autoscaling introduce variance. Define metrics, test harness, load generation, statistical methods to account for noise, and steps to ensure repeatability and fairness.

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