Machine Learning Engineer · Onsite · Multiple Types

Meta — Machine Learning Engineer ❌ Failed

Level: Mid-Level · E4

Round: Onsite · Type: Multiple Types · Difficulty: 6/10 · Duration: 240 min · Interviewer: Unfriendly

Topics: Behavioral Questions, Graph Traversal, Algorithms, Recommendation Systems, Machine Learning System Design, XGBoost

Location: Menlo Park, CA

Interview date: 2026-01-22

Got offer: False

Summary

Round 1: Behavioral (BQ)

Question: General behavioral questions. I was told this round went very well.

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Round 2: Coding

Question: Graph traversal problem. I solved it with hints from the interviewer.

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Round 3: AI Coding

Question: A previously seen problem, which made it easy to solve. I used AI to fix minor bugs.

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Round 4: Machine Learning System Design (ML SD)

Question: Classic recommendation system design. The questions were very open-ended, focusing on potential problems with labels and XGBoost.

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Details

Preparation Tips & Key Takeaways

What I Learned

• My behavioral round was strong, but my coding performance was average due to lack of preparation.
• I should have prepared more thoroughly for the ML system design round.
• The ML SD process here differs from other companies, with more focus on potential problems rather than solutions.

Recommended Preparation

Coding Practice

• Practice graph traversal algorithms.
• Focus on problems that require hints from the interviewer.

System Design

• Study recommendation system design.
• Review potential problems with labels and XGBoost in ML models.

Behavioral Questions

• Prepare STAR stories to showcase my strengths and experiences.

Resources I Recommend

• Review classic recommendation system architectures.
• Practice writing unit tests for AI coding problems.

Common Pitfalls to Avoid

• Avoid neglecting coding practice, as it can lower the bar for other rounds.
• Be prepared for open-ended questions in ML system design rounds.

The coding question I got was:

`java class Mouse {

/**
* Moves to one of the directions (left, right, up, down) and returns false if you can't move and true if you can.
*/
public boolean move(Direction direction);

/**
* Returns true if there is a cheese in the current cell.
*/
public boolean hasCheese();

/**
* Should return true and leave the mouse at that location or false if we can't find cheese and return the mouse back to where it started.
*/
public boolean getCheese() {
	// your code goes here
}

} `

LeetCode similar: LeetCode 2611