Technical practice
How would you choose an approach for classification, regression, clustering, or recommendations?
What to coverPreparation suggestion: Explain how the task, available labels, data quality, and intended use shape the choice of approach and baseline. Describe task-appropriate validation measures and the trade-off between model complexity and deployment needs.
How would you prepare and validate a custom dataset for an ML model?
What to coverPreparation suggestion: Cover data checks, preprocessing, train/validation separation, and augmentation that preserves valid labels. Explain how you would check accuracy and robustness on representative real-world data.
How would you debug a slow or incorrect image-processing pipeline?
What to coverPreparation suggestion: Walk through isolating preprocessing, NumPy operations, OpenCV transformations, and model inference before changing the model. Discuss checks for correctness alongside profiling, since a faster pipeline is not useful if its outputs change unexpectedly.
How would you build a retrieval-augmented generation system using an LLM and external data?
What to coverPreparation suggestion: Explain document preparation, retrieval through a vector database, and how retrieved context reaches a model such as GPT or LLaMA. Discuss trade-offs among retrieval relevance, response quality, latency, and updating the source data.
How would you diagnose poor answers from a RAG system?
What to coverPreparation suggestion: Separate retrieval failures from failures to use retrieved context accurately, and describe how you would inspect examples at each stage. Explain how an evaluation set would help determine whether an optimization improves answers rather than just changing them.
How would you design and validate a face-recognition system?
What to coverPreparation suggestion: Discuss an embedding-based approach such as FaceNet or ArcFace, including matching thresholds and the consequences of false matches and missed matches. Address custom dataset quality, augmentation, and robustness across realistic image conditions.
How would you combine object detection with liveness detection?
What to coverPreparation suggestion: Explain the distinct purpose of locating an object or face and assessing liveness, then describe where each check fits in an inference flow. Discuss accuracy and latency trade-offs when the application must operate in real time.
How would you deploy a model as a scalable production service?
What to coverPreparation suggestion: Describe a REST API inference path and the roles Docker, Kubernetes, and MLOps tools can play in packaging, scaling, and managing deployment. Explain what you would validate before release and how you would monitor the deployed model.
How would you meet a real-time inference target, including on an edge device when required?
What to coverPreparation suggestion: Identify where latency occurs across preprocessing, inference, and serving, then explain how you would measure improvements. Discuss model optimization and the trade-offs among speed, accuracy, and available compute without assuming a particular device.
What would you investigate if a deployed model's results degraded?
What to coverPreparation suggestion: Compare current inputs and outputs with validation data and earlier production behaviour, checking for data changes and pipeline or model issues. Explain how monitoring and reproducible validation would help isolate the cause and assess a fix.
Behavioural practice
Tell me about a time you resolved a difficult dataset or model-debugging problem.
What to coverPreparation suggestion: Use a real example to describe the situation, the checks you performed, and why you chose your fix. Close with the measured result or what remained unresolved.
Describe a time you improved a model's accuracy or robustness.
What to coverPreparation suggestion: Set out the original limitation, your actions across data preparation, training, or validation, and the evidence used to assess the change. State the result and any trade-off you observed.
Tell me about a time you balanced model quality against application performance.
What to coverPreparation suggestion: Describe the practical constraint, the alternatives you evaluated, and the decision you made. Give the resulting effect on quality and performance, including any limitation you had to accept.
Describe a time you took a model from development toward deployment or monitoring.
What to coverPreparation suggestion: Explain your own responsibilities, the deployment or monitoring challenge, and the actions you took. End with the observed result and what the experience changed about your approach.