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Applied Scientist Interview Questions

Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.

9403
Questions
546
Companies
11
Topics
8
Languages

Showing 1–12 of 12 results

  • AmazonMediumApplied Scientist
    Design LFU cache with distributed extension

    This question evaluates understanding of cache design and frequency-based eviction policies, efficient data structures that support O(1) operations, and techniques for approximate frequency estimation and summarization in distributed streaming environments.

    Coding & AlgorithmsOnsite
  • AmazonMediumApplied Scientist
    Find shortest path in a grid with obstacles

    This question evaluates understanding of pathfinding in grid-based environments, graph traversal concepts, and algorithmic complexity when navigating obstacles and boundary constraints in an unweighted 2D search space.

    Coding & AlgorithmsOnsite
  • AmazonMediumApplied Scientist
    Implement K-means and solve interval/frequency tasks

    This multi-part question evaluates understanding of K-means clustering, interval-merging algorithms, and frequency-based top-k retrieval, assessing competencies in unsupervised learning concepts, algorithmic problem solving, data structures, and complexity analysis.

    Coding & AlgorithmsOnsite
  • AmazonMediumApplied Scientist
    Implement Multi-Head Attention from Scratch in NumPy

    This problem tests your understanding of Transformer components by requiring an implementation of Multi-Head Scaled Dot-Product Attention using only NumPy, emphasizing matrix manipulations and numerical stability.

    Coding & AlgorithmsOnsiteTransformersNumPyAttention
  • AmazonMediumApplied Scientist
    Implement PyTorch training loop

    This question evaluates practical implementation skills in PyTorch, focusing on model and device management, batch-wise training mechanics, gradient handling, and optimizer interaction.

    Coding & AlgorithmsOnsite
  • AmazonMediumApplied Scientist
    Implement Top-p (Nucleus) Sampling in NumPy

    This problem tests your ability to implement the nucleus sampling algorithm from scratch using NumPy, focusing on probability distribution processing and efficient array masking.

    Coding & AlgorithmsOnsiteNumPyNLPProbability
  • AmazonMediumApplied Scientist
    Implement decoder-only GPT-style transformer

    This question evaluates implementation-level mastery of transformer architectures, including multi-head masked self-attention, position-wise feed-forward networks, residual connections, and precise tensor-shape reasoning for a decoder-only language model, within the Coding & Algorithms domain of deep learning and neural network engineering.

    Coding & AlgorithmsOnsite
  • AmazonMediumApplied Scientist
    Implement integer division without using division

    This question evaluates proficiency in implementing low-level integer arithmetic and algorithmic optimization, including correct handling of overflow and edge cases within 32-bit signed integer constraints.

    Coding & AlgorithmsOnsite
  • AmazonMediumApplied Scientist
    Implement inventory allocation with backorders

    Implement inventory allocation with backorders evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Coding & AlgorithmsOnsite
  • MicrosoftMediumApplied Scientist
    Fewest Distinct Values to Delete So at Least Half the Array Is Removed

    A coding question that asks for the fewest distinct values whose complete deletion removes at least half of an integer array. It tests reasoning about how often each value occurs, proving that a choice is minimal, and the exact meaning of half when the array length is odd.

    Coding & AlgorithmsOnsite
  • MicrosoftMediumApplied Scientist
    Insert Spaces to Rebuild a Sentence from Dictionary Words

    A coding question that asks you to insert spaces into a string that lost them so that every piece is a dictionary word, returning the smallest valid sentence or None when no split exists. It tests string segmentation with dictionary lookups, handling of impossible inputs, and a canonical tie-breaking rule.

    Coding & AlgorithmsOnsite
  • MicrosoftMediumApplied Scientist
    Maximum Subarray Sum of an Array Repeated K Times

    A coding question that first asks for the largest sum of a non-empty contiguous subarray, then for the same quantity when the array is written out k times back to back. It tests subarray reasoning across copy boundaries, all-negative inputs, and sums that overflow 32-bit integers.

    Coding & AlgorithmsOnsite