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Glean·Machine Learning Engineer·Onsite - System Design / Architecture·Senior

Senior
Jun 2026

Summary

Did an ML design round at Glean for an MLE role. One question, 60 minutes, focused on computing distances between employees. Interesting problem space but the session left me with a lot of unanswered questions about what they actually wanted.

Questions Asked (1)

Q1

Design a system that computes a distance or similarity score between any two employees in an organization.

System DesignData ModelingTechnical Trade-offs
Author's notes

This is the kind of question that sounds deceptively scoped until you realize you need to define what 'distance' even means before writing a single line of pseudocode.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the business objective and what 'distance' means in this context, then propose a graph-based representation of the organization where nodes are employees and edges are weighted by various signals. Outline how to compute similarity using embeddings and graph algorithms, and discuss trade-offs between accuracy, scalability, and privacy.

Pro tip: Emphasize that the system should be designed for interpretability and privacy, as employee data is sensitive; suggest using techniques like federated learning or differential privacy to build trust.

1. Clarify Requirements and Define Distance

Ask questions to understand the use case (e.g., team recommendation, expertise search) and define what constitutes distance/similarity (e.g., based on skills, interactions, hierarchy).

2. Data Modeling and Feature Extraction

Identify data sources (org chart, collaboration tools, HR records) and extract features such as skills, projects, communication patterns, and reporting lines.

3. Choose Similarity Metrics and Algorithms

Select appropriate metrics (e.g., cosine similarity, Jaccard, graph distance) and algorithms (e.g., node embeddings, random walks) to compute pairwise scores efficiently.

4. System Architecture and Scalability

Design a scalable pipeline for feature computation, embedding generation, and similarity search, considering batch vs. real-time processing and indexing structures.

5. Evaluate and Iterate

Define evaluation metrics (e.g., precision@k, user feedback) and plan for monitoring, updating models, and handling privacy concerns.

Key Points to Mention

  • Graph representation of the organization with nodes and edges
  • Use of embeddings (e.g., node2vec, GraphSAGE) to capture structural and attribute information
  • Trade-offs between different similarity metrics and their computational complexity
  • Scalability considerations: approximate nearest neighbor search (e.g., FAISS, Annoy) for large-scale similarity queries
  • Privacy and ethical considerations: anonymization, differential privacy, access control
  • Evaluation strategies: offline metrics and online A/B testing with user feedback

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.