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Model Monitoring and Observability Questions

Covers the design, implementation, operation, and continuous improvement of monitoring, observability, logging, alerting, and debugging for machine learning models and their data pipelines in production. Candidates should be able to design instrumentation and telemetry that captures predictions, input features, request context, timestamps, and ground truth when available; define and track online and offline metrics including model quality metrics, calibration and fairness metrics, prediction latency, throughput, error rates, and business key performance indicators; and implement logging strategies for debugging, auditing, and backtesting while addressing privacy and data retention tradeoffs. The topic includes detection and diagnosis of distribution shifts and concept drift such as data drift, label drift, and feature drift using statistical tests and population comparison measures (for example Kolmogorov Smirnov test, population stability index, and Kullback Leibler divergence), windowed and embedding based comparisons, change point detection, and anomaly detection approaches. It covers setting thresholds and service level objectives, designing alerting rules and escalation policies, creating runbooks and incident response processes, and avoiding alert fatigue. Candidates should understand retraining strategies and triggers including scheduled retraining, automated retraining based on monitored signals, human in the loop review, canary and phased rollouts, shadow deployments, A versus B experiments, fallback logic, rollback procedures, and safe deployment patterns. Also included are model artifact and data versioning, data and feature lineage, reproducibility and metadata capture for auditability, continuous validation versus scheduled validation tradeoffs, pipeline automation and orchestration for retraining and deployment, and techniques for root cause analysis and production debugging such as sample replay, feature distribution analysis, correlation with upstream pipeline metrics, and failed prediction forensics. Senior expectations include designing scalable telemetry pipelines, sampling and aggregation strategies to control cost while preserving signal fidelity, governance and compliance considerations, cross functional incident management and postmortem practices, and trade offs between detection sensitivity and operational burden.

MediumTechnical
0 practiced
Set SLO targets and an error-budget policy for a fraud-detection model that must balance latency, false-positive rate (FPR), and coverage (fraction of transactions scored). Propose concrete numeric targets, define how errors consume budget, and explain how product and legal teams should be informed when budgets are depleted.
EasyTechnical
0 practiced
You are the SRE responsible for model telemetry. Define a minimal per-prediction telemetry schema to capture necessary signals for monitoring, alerting, and post-incident debugging. Include fields such as prediction value, confidence/probability, input feature pointers or feature-hash, request-context (request-id, user/session id), timestamp, model-version, and ground-truth when available. Explain why each field is needed and discuss tradeoffs (privacy, storage cost, queryability).
EasyBehavioral
0 practiced
Tell me about a time you were on-call for a production ML model that degraded in quality. Describe the Situation, Task, Actions you took to detect/mitigate, the Result, and what remediation or process changes you implemented afterward (use STAR format).
HardTechnical
0 practiced
Design an online change-point detection approach for high-dimensional embedding streams using algorithms such as ADWIN or CUSUM. Explain how you would reduce dimensionality, choose summary statistics or distance metrics to monitor, maintain the detector state efficiently in streaming, and estimate detection latency and false-positive tradeoffs.
MediumTechnical
0 practiced
Compare Kolmogorov–Smirnov (KS), Population Stability Index (PSI), and Kullback–Leibler divergence (KLD) as tools for detecting distributional drift. For each test explain sensitivity to sample size, interpretability for engineers, numerical stability, and situations where one is preferred over the others.

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