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Meta·Machine Learning Engineer·Technical Phone Screen·Intermediate

Intermediate
Apr 2026

Summary

Quick ML engineer screen at Meta, basically just one coding question about binary representation. Nothing fancy, felt more like a warmup than a real technical round.

Questions Asked (1)

Q1

Write a function that returns the binary representation of a given integer.

Algorithms & Data Structures
Author's notes

Seemed straightforward but I second-guessed myself on edge cases like negative numbers and zero.

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AI HintsAI Generated

Suggested Approach

Clarify the input constraints (e.g., signed vs unsigned, negative numbers, zero) and then present a solution using bitwise operations or division by 2. Discuss time and space complexity, and consider edge cases like 0 and negative integers.

Pro tip: Mention that Python's bin() function returns a string with '0b' prefix, so you'd strip it for a pure binary representation, but in an interview, implement the logic manually to show understanding.

1. Clarify requirements

Ask about the integer range, handling of negative numbers, and expected output format (e.g., string, list of bits).

2. Choose an approach

Decide between iterative division by 2 or bitwise operations (shifts and masks). For negative numbers, consider two's complement or absolute value with sign handling.

3. Implement the function

Write clean code, handling edge cases like 0 and negative numbers. Use a loop to build the binary string from least significant bit to most, then reverse.

4. Test with examples

Walk through examples: positive (e.g., 5 -> '101'), zero (0 -> '0'), and negative (e.g., -5 -> '-101' or two's complement depending on clarification).

5. Analyze complexity

State time complexity O(log n) and space complexity O(log n) for the output string, and discuss potential optimizations.

Key Points to Mention

  • Bitwise operations: using right shift (>>) and bitwise AND (&) to extract bits.
  • Handling negative numbers: two's complement representation or sign-magnitude approach.
  • Edge cases: zero, negative numbers, and large integers.
  • Time and space complexity: O(log n) time and space.
  • Alternative approaches: using built-in functions like bin() in Python, but implementing manually for interview.
  • Recursion vs iteration: trade-offs in readability and performance.

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