Staffing an AI Project and Handling Personal Identifiers in LLM Training Data
Company: Microsoft
Role: Product Manager
Category: Machine Learning
Difficulty: medium
Interview Round: Other
This question has two parts. First, describe the roles on your AI project team and how they work together. Second, explain how you would approach training a large language model when the training data contains usernames and email addresses.
### Clarifying Questions
- If I have not been on an AI project team, may I describe the team I would assemble for one?
- Where does the data come from: public web text, logs from a consumer product, or content that business customers store in Microsoft services, and what did users agree to when it was collected?
- Is the plan to train a model from scratch or to fine-tune an existing one for a single feature, and does that feature ever need to output real email addresses?
- Which jurisdictions do the affected users live in, since that changes consent and deletion obligations?
### Part 1 — Who does what on the team
Name each role on the team, what it owns, and where you as the product manager fit in.
```hint Follow the model's lifecycle
Trace the work from data through training, evaluation, launch and monitoring, and ask who owns each step. Some of the owners sit outside engineering.
```
#### What This Part Should Cover
- The core build roles and what each owns across data, modeling, evaluation and serving.
- The partners outside engineering, such as privacy, legal, security and responsible AI review, and when they get involved.
- How decisions are made, and where the PM adds value versus deferring to specialists.
### Part 2 — Usernames and emails in the training data
The dataset you plan to train on includes usernames and email addresses. How would you handle it?
```hint Question the need first
Before picking a technique, ask whether the model needs these identifiers at all and whether you are allowed to use them. The answers decide between removing, replacing or protecting them.
```
#### What This Part Should Cover
- Whether the data may be used at all: consent, purpose and data minimization.
- How identifiers are detected and removed or replaced, and what each option costs in model quality.
- How to verify that the trained model does not leak identifiers, and how to handle later deletion requests.
### What a Strong Answer Covers
- Clear decision rights: who decides on data use versus model quality, and how disagreements between them are escalated.
- Privacy controls across the whole pipeline, from collection through training to model outputs, rather than a single "anonymize it" step.
- An explicit trade-off between privacy protection and model usefulness, backed by measurement.
- Checks that must pass before launch and monitoring that continues after it.
### Follow-up Questions
- Your scientists say removing usernames hurts the model because usernames carry who-replied-to-whom context in discussion threads. How do you resolve it?
- After launch, a user asks for their data to be deleted, and their email address was in the training set. What do you do?
- A red-team test gets the model to output a real email address from the training data. Do you delay the launch, and which fixes do you consider?
Overview: A two-part Microsoft product manager question: describe the roles on an AI project team and how they collaborate, then explain how to train a large language model on data that contains usernames and email addresses. It tests cross-functional ownership, privacy judgment, data minimization and leak testing.