Technical practice
How would you design a module to turn raw datasets into structured data?
What to coverSuggested answer focus: Walk through gathering, cleaning, validation, transformation and a defined output structure. Explain how you would make the steps systematic and test the resulting data.
How would you diagnose an inconsistency in data flowing through the Data Hub?
What to coverSuggested answer focus: Trace the issue through source data, transformations and the relevant schema to locate its cause. Explain how you would assess the risk, document evidence and flag it to the appropriate collaborators.
How would you make a data-processing solution reusable and scalable?
What to coverSuggested answer focus: Discuss modular interfaces, repeatable validation and how you would check behaviour as data volumes or sources change. Explain how GitLab version control would help the team review and maintain changes.
How would you improve an annotation workflow with SMEs and a labeling team?
What to coverSuggested answer focus: First establish the domain requirements and where annotators encounter ambiguity or repeated work. Then describe how you would test a tool or process change and use technical feedback to refine it.
How would you integrate data across relational, NoSQL and graph databases?
What to coverSuggested answer focus: Compare the structures each database supports and explain how schemas and relationships affect integration. Describe checks you would use to preserve meaning and consistency when moving or combining data.
How would you design features from cleaned data for an ML initiative?
What to coverSuggested answer focus: Connect feature choices to the task and available domain knowledge, then explain how you would check data quality and usefulness. Discuss the trade-off between informative features and features that are difficult to maintain or validate.
When would you combine traditional ML with LLMs, embeddings, ontologies or knowledge graphs?
What to coverSuggested answer focus: Compare what each approach contributes to a task and where a simpler approach may suffice. Describe how you would test whether a hybrid workflow adds value rather than assuming it does.
How would you decide between using a pre-trained model and fine-tuning it on internal data?
What to coverSuggested answer focus: Consider task fit, the amount and quality of internal data, and the cost of training and maintenance. Explain what evidence you would seek before choosing an approach.
How would you evaluate and validate a model trained on internal data?
What to coverSuggested answer focus: Define success measures that match the task, use an appropriate separation of training and evaluation data, and inspect errors. Explain how you would detect whether an apparent improvement generalizes.
How would you run and document an experiment after an initial ML result disappoints?
What to coverSuggested answer focus: State a hypothesis, change a defined aspect of the data or model, and compare results against the initial run. Describe what you would record and share so the team can understand the outcome and next step.
Behavioural practice
Tell me about a time you clarified domain requirements with subject matter experts.
What to coverSuggested preparation: Use a real example to set out the situation, the questions you asked and how you translated the answers into data or labeling work. Close with the result, including any remaining uncertainty.
Tell me about a time you identified a data inconsistency or risk.
What to coverSuggested preparation: Describe how you noticed and investigated it, whom you informed, and what action followed. State the result without overstating what you could verify.
Tell me about a time you had to learn a new tool or concept to complete work.
What to coverSuggested preparation: Explain the task, how you learned and tested the concept, and how you applied it. Give the outcome and what you would do differently next time.
Tell me about a time you balanced a delivery deadline with data quality.
What to coverSuggested preparation: Describe the deadline and quality concern, the trade-off you communicated, and the action you took. Explain the result and how stakeholders understood any remaining risk.
Tell me about a time you shared experimental findings with cross-functional partners.
What to coverSuggested preparation: Set out the experiment and the audience, then explain how you communicated results and limitations. Describe the decision or next step that followed.