Topic
Coding & Algorithms interview questions
3276 Coding & Algorithms questions from 366 companies, with hints, runnable code and solution walkthroughs.
273 easy2539 medium464 hard
Coding & Algorithms interview questions by the numbers
Last updated
Katkat has 3,276 Coding & Algorithms interview questions from 366 companies; the most come from Amazon (7%), Meta (7%) and Google (6%). By difficulty: 8% easy, 78% medium and 14% hard. The most common round is Technical Screen (52%). Frequent concepts include Algorithms, Data Structures, Arrays and Greedy.
Companies (366)
Difficulty
- Easy8% · 273
- Medium78% · 2539
- Hard14% · 464
Interview rounds
- Technical Screen52% · 1706
- Onsite33% · 1080
- Online Assessment13% · 427
- HR Screen1% · 37
- Other1% · 26
Roles
- Software Engineer80% · 2629
- Machine Learning Engineer8% · 253
- Data Scientist7% · 241
- Data Engineer1% · 45
- Backend Engineer1% · 26
Frequent concepts
- Algorithms9% · 302
- Data Structures7% · 228
- Arrays5% · 176
- Greedy5% · 164
- Optimization5% · 151
- Hash Map4% · 124
Most mentioned in interview experiences
- 1.Solve Algorithmic Challenges in Online Coding Assessments15 reports
- 2.Solve LeetCode string and list problems11 reports
- 3.Solve sliding-window and heap problems8 reports
- 4.Implement LRU cache with O(1) ops7 reports
- 5.Implement and Analyze an LRU Query Cache6 reports
- 6.Determine Length of Longest Unique Substring5 reports
- 7.Match-3 Grid: Find Horizontal and Vertical Runs, Then Clear and Drop Cells5 reports
- 8.Design a single- and multi-threaded web crawler4 reports
- 9.Find an Exit in a URL Maze4 reports
- 10.Find deployable slots in a recurring week from allowed and freeze windows4 reports
Counted from 781 candidate interview experiences on Katkat. How we collect and count
Showing 1591–1620 of 3276 results
This question evaluates proficiency in graph algorithms, shortest-path computation, and algorithmic optimization when augmenting a directed weighted graph with additional unit-weight edges.
MathWorksSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to handle currency conversion using graph pathfinding (multiplicative weights) and implement a custom pagination algorithm that balances item distribution while respecting original ordering.
MavenclinicSoftware EngineerCoding & AlgorithmsOnsiteParcels arrive one at a time for a bank of numbered lockers, each requesting a preferred locker and overflowing to the next higher-numbered empty one if it's taken. Decide whether every parcel finds a locker. Tests precise rule-following and an efficient alternative to simulating forward scans one slot at a time.
MercorMachine Learning EngineerCoding & AlgorithmsOnsiteGiven a list of pairwise currency exchange rates such as USD to GBP at 0.77, compute the rate from a source currency to a target currency, converting through intermediate currencies and using rates in reverse where needed. It tests reasoning about chained conversions, unknown or unreachable currencies, and a clear time and space complexity analysis.
MercorSoftware EngineerCoding & AlgorithmsOnsiteDesign and implement an in-memory referral network as a directed acyclic graph (DAG) supporting cycle-safe edge insertion, depth-bounded reachability queries, and expected reward computation under geometric decay.
MercorMachine Learning EngineerCoding & AlgorithmsOnsiteThis question tests your ability to apply Breadth-First Search (BFS) on an augmented state space where path state includes both coordinates and remaining resources.
MercorSoftware EngineerCoding & AlgorithmsTechnical ScreenAdd two non-negative integers that are given as decimal digit strings, possibly thousands of digits long, and return the sum as a string without converting to built-in numbers. Tests digit-by-digit addition with carries, inputs of unequal length and canonical output without leading zeros.
MetaSoftware EngineerCoding & AlgorithmsOtherPreprocess a sorted array derived from a static BST to answer many inclusive range queries. Use binary-search boundaries and wide prefix sums to return both the sum and count for each range without rescanning the tree.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis set of four problems evaluates algorithmic competencies including ASCII string processing and character classification, array transformation and operation-count reasoning, cost-minimization for enforcing monotonicity under only-increase constraints, and time-based simulation of resource scheduling with recharge cycles.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to manipulate graph-like data structures to perform neighbor analysis and efficient set operations to rank potential connections.
MetaMachine Learning EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates web API development and backend engineering competencies, including FastAPI usage, Python type hints, Pydantic-based request/response validation, error handling, in-memory state management, and modular router/service/model layering, and it belongs to the Coding & Algorithms category with a focus on backend web service and API design. It is commonly asked to assess practical ability to deliver production-ready REST endpoints with proper validation and error handling under constrained resources, and the level of abstraction required is primarily practical implementation with attention to architectural design.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to implement a graph-based recommendation algorithm using common neighbors and popularity constraints to rank potential connections.
MetaMachine Learning EngineerCoding & AlgorithmsOnsiteConvert an absolute Unix-style file path into its canonical form by collapsing repeated slashes, dropping single-dot segments, resolving double-dot segments against the parent directory, and treating other dot sequences as ordinary names. It tests careful string parsing and edge cases such as the root directory.
MetaSoftware EngineerCoding & AlgorithmsOnsiteDetermine whether a string can be transformed into a palindrome by removing at most k characters. Tests dynamic programming, palindrome properties, and recursive search with branch bounding.
MetaSoftware EngineerCoding & AlgorithmsOnsiteDecide whether an abbreviation made of lowercase letters and decimal skip counts matches a given word, where each number skips that many characters and any number with a leading zero is invalid. It tests careful string scanning, multi-digit number parsing and end-of-input boundary checks.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates understanding of array and matrix manipulation, sliding-window and streaming statistics, and appropriate data-structure choices for maintaining aggregates and order-statistics such as moving averages and sliding-window medians.
MetaMachine Learning EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates skill in matrix manipulation and algorithmic reasoning, specifically understanding diagonal traversal, equality checks, and handling boundary conditions such as empty matrices, single-row or single-column inputs, and negative values.
MetaMachine Learning EngineerCoding & AlgorithmsTechnical ScreenThis problem tests the ability to optimize a two-step decision process by maintaining track of the best previous state, requiring a linear scan approach.
MetaSoftware EngineerCoding & AlgorithmsOnsiteTests bitmask representation, backtracking with pruning, and combinatorial optimization under character-uniqueness constraints.
MetaSoftware EngineerCoding & AlgorithmsOnsiteMeta software-engineer technical-screen coding question: deep-copy a singly linked list whose nodes carry an arbitrary random pointer (which may be null, point backward, or form cycles). It tests both the O(n)-space hash-map solution and the O(1)-auxiliary-space in-place weaving technique, plus reasoning about pointer integrity, cycle safety, and verifying the copy is structurally equal to and isolated from the original.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenA coding question asking you to merge many integer arrays, each already sorted in non-decreasing order, into a single sorted array that keeps every duplicate value. It tests multi-way merging, efficiency as the number of input arrays grows, and edge cases such as empty inputs and arrays of different lengths.
MetaSoftware EngineerCoding & AlgorithmsOnsite- Compute BST range sumMedium
This question evaluates understanding of binary search tree properties, traversal techniques, and the ability to implement both recursive and iterative algorithms while reasoning about time and space complexity.
MetaSoftware EngineerCoding & AlgorithmsOnsite This problem tests your ability to manage state in nested processes using a stack data structure to track the exclusive execution time of functions based on a log of start and end events.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis Coding & Algorithms question in the Data Engineer domain evaluates grouping and top‑k aggregation concepts, testing the ability to combine per-category aggregation with selection under a uniqueness constraint.
MetaData EngineerCoding & AlgorithmsTechnical ScreenThis question tests the ability to trade preprocessing time for query performance using prefix sum arrays to efficiently calculate the sum of elements within a specified range.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question tests the ability to implement a sliding window algorithm to compute the average of contiguous subarrays, emphasizing optimization of time complexity.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenCompute maximum stock profit for both one transaction and unlimited nonoverlapping transactions in linear time, returning zero when no positive trade is available.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Compute binary tree diameter states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates algorithmic problem-solving with binary trees, focusing on tree traversal techniques, recursion versus iterative implementations, and analysis of time and space complexity including worst-case input shapes such as skewed trees.
MetaData ScientistCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's ability to manipulate nested dictionary data structures and perform aggregate capacity computations, assessing data transformation, mapping, and set-based reasoning skills relevant to a Data Engineer within the Coding & Algorithms domain.
MetaData EngineerCoding & AlgorithmsTechnical Screen