Applied Scientist Interview Questions

Showing 1–20 of 20 results

• AmazonMedium·Applied Scientist
  Check if adding edge creates cycle in digraph

  This question evaluates understanding of graph algorithms, reachability, and algorithmic complexity by determining whether adding a directed edge would introduce a cycle in an otherwise acyclic directed graph.

  Coding & AlgorithmsTechnical Screen
• AmazonMedium·Applied 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
• AmazonMedium·Applied Scientist
  Determine if all courses can be completed

  This problem tests your ability to model prerequisites as a directed graph and detect cycles to determine if a valid topological ordering exists.

  Coding & AlgorithmsTechnical ScreenGraphsTopological SortDFS
• AmazonMedium·Applied 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
• AmazonMedium·Applied Scientist
  Find shortest transformation steps in a word graph

  This question evaluates a candidate's ability to model string transformations as a graph, apply graph traversal and shortest-path reasoning, and manage efficient string-based search and data-structure choices within the Coding & Algorithms domain.

  Coding & AlgorithmsTechnical Screen
• AmazonMedium·Applied Scientist
  Find two numbers that sum to target

  This question evaluates a candidate's competency in basic algorithmic problem-solving within the Coding & Algorithms domain, focusing on array manipulation, pair-sum reasoning, and analysis of time-space trade-offs.

  Coding & AlgorithmsTechnical Screen
• AmazonMedium·Applied Scientist
  Highest Average-Salary Team in an Org Chart

  Tests bottom-up tree traversal to compute subtree aggregates (sum and count) and identify an optimal node using multi-level tie-breaking rules.

  Coding & AlgorithmsTechnical Screentreedfsrecursion
• AmazonMedium·Applied 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
• AmazonMedium·Applied 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
• AmazonHard·Applied Scientist
  Implement Optimal Bucket Batching

  This question evaluates algorithm design and optimization skills, focusing on combinatorial partitioning and batching strategies, efficient utilization of parallel GPUs, and time/space complexity analysis relevant to ML data pipelines.

  Coding & AlgorithmsTechnical Screen
• AmazonMedium·Applied 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
• AmazonMedium·Applied 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
• AmazonMedium·Applied Scientist
  Implement binary search lower/upper bounds

  Implement lower_bound and upper_bound on a non-decreasing sorted array using iterative binary search in O(log n) time and O(1) space. This Amazon ML engineer screen tests precise boundary handling, loop-invariant reasoning, and edge cases like duplicates, empty arrays, and out-of-range targets.

  Coding & AlgorithmsTechnical Screen
• AmazonMedium·Applied 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
• AmazonMedium·Applied 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
• AmazonMedium·Applied 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
• AmazonMedium·Applied Scientist
  Merge Overlapping Time Ranges

  This problem tests your ability to manipulate arrays of intervals by sorting and merging, evaluating your proficiency with pointer manipulation and interval arithmetic.

  Coding & AlgorithmsTechnical ScreenArraysSortingIntervals
• MicrosoftMedium·Applied 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
• MicrosoftMedium·Applied 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
• MicrosoftMedium·Applied 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