Technical practice
How would you turn a business problem into a predictive-modeling task?
What to coverSuggested preparation: Explain how you would define the target, establish a baseline and choose evaluation measures that reflect the business objective. Address how you would check whether the available data can support the proposed prediction.
How would you prepare large structured and unstructured datasets for modeling?
What to coverSuggested preparation: Discuss data quality checks, feature engineering and ways to handle missing or inconsistent information. Explain how you would prevent information leakage when creating training and evaluation datasets.
How would you use SQL and ELT or ETL to produce reliable model inputs?
What to coverSuggested preparation: Describe transformations and joins across relational data, including checks for duplicate records and unexpected row counts. Explain how you would validate the resulting dataset and make transformations reproducible.
When would you choose a statistical model over a deep-learning model?
What to coverSuggested preparation: Compare the approaches using data volume, interpretability, performance and operating cost. Explain how you would test whether added complexity provides a meaningful improvement.
How would you evaluate a Transformer or LLM for a business use case?
What to coverSuggested preparation: Explain how you would establish a simpler baseline and assess output quality, failure modes, latency and cost. Discuss when a generative approach would be inappropriate for the task.
How would you design retrieval using embeddings and a vector database?
What to coverSuggested preparation: Cover document preparation, embedding and retrieval choices, and evaluation of both retrieved material and final answers. If discussing LangChain or LangGraph, explain what the framework adds and when a simpler implementation would suffice.
When is reinforcement learning appropriate, and how would you evaluate an optimization approach?
What to coverSuggested preparation: Distinguish a sequential decision problem from one suited to conventional prediction or optimization. Explain how you would define the objective and constraints, then assess the approach against a simpler baseline.
How would you build and deploy an end-to-end ML pipeline on a cloud platform?
What to coverSuggested preparation: Walk through data preparation, training, evaluation, deployment and reproducibility using MLOps practices. Address reliability and scaling trade-offs; AWS is preferred in the posting, but no specific service is named.
How would you investigate a decline in production model performance?
What to coverSuggested preparation: Explain how monitoring could help distinguish data changes, pipeline faults and model degradation. Describe how you would verify the cause and decide whether to fix the pipeline, retrain or roll back.
How would you maintain the quality of a production AI or ML codebase?
What to coverSuggested preparation: Discuss code review, documentation, version control and CI/CD for model and pipeline changes. Explain how you would use Python, SQL, R or shell scripting where appropriate without assuming that every task needs every language.
Behavioural practice
Tell me about a time you clarified an ambiguous stakeholder request.
What to coverSuggested preparation: Use a real situation to explain what was unclear, the questions you asked and the action you took to agree on a measurable goal. State the result and how you communicated any remaining limitations.
Describe a time you worked with data engineers or technical teams to deliver a data solution.
What to coverSuggested preparation: Give the situation, your responsibilities and the actions you took to coordinate data or deployment work. Explain the result, including how you resolved any handoff or ownership issue.
Tell me about a model or data analysis that did not meet expectations.
What to coverSuggested preparation: Describe the situation and the evidence that showed a problem, then explain how you diagnosed it and changed course. State the result without presenting an improvement that did not occur.
Describe a time you improved quality through code review or documentation.
What to coverSuggested preparation: Set out the quality concern, your specific action and how you worked with others to address it. Explain the result in terms of maintainability, reliability or clarity.
Tell me about a time you assessed whether to adopt a new AI or data-science technique.
What to coverSuggested preparation: Describe the situation, how you compared the technique with an existing approach and what evidence informed your recommendation. State the decision and result, including any trade-offs you communicated.