Software Engineer Coding & Algorithms Interview Questions

Practice 2,743 real Coding & Algorithms interview questions for Software Engineer roles. From companies including Meta, Amazon, Google, Uber, Microsoft.

2.7k Questions 325 Companies08.16.2026
Showing 20 results
Role
Datadog logo
Datadog
Medium
Software Engineer

Implement write with internal buffer

Implement a buffered writer over an expensive sink API. You are given a function writeToDevice(byte[] chunk) that may accept at most M bytes per call ...

Coding & Algorithms
0
0
8 people solved
Sep 6, 2025
DoorDash logo
DoorDash
Medium
Software Engineer

Design dasher-to-order assignment algorithm

You are building a real-time 'dasher picker' that assigns delivery drivers (Dashers) to incoming orders. Define objective(s) (e.g., minimize ETA and c...

Coding & Algorithms
1
0
13 people solved
Sep 6, 2025
Amazon logo
Amazon
Medium
Software Engineer

Find returning users from access logs

Given an unordered log of web access events, identify which users are returning (i.e., they have visited on at least two different calendar days). Eac...

Coding & Algorithms
1
0
8 people solved
Sep 6, 2025
Meta logo
Meta
Medium
Software Engineer

Design an in-memory database with TTL and history

Design and implement an in-memory key–field–value store with monotonic timestamps. Keys and fields are strings; values are integers. Provide these API...

Coding & Algorithms
9
0
100 people solved
Sep 6, 2025
Meta logo
Meta
Medium
Software Engineer

Implement power and balance-parentheses algorithms

Design and implement two algorithms: 1) Fast exponentiation: Implement a function pow(x, n) that returns a real number x raised to an integer exponent...

Coding & Algorithms
2
0
31 people solved
Sep 6, 2025
Meta logo
Meta
Medium
Software Engineer

Implement BST vertical traversal and list conversion

Given the root of a binary search tree (BST): 1) Implement vertical order traversal: assign the root column 0, left child column −1, right child colum...

Coding & Algorithms
2
0
46 people solved
Sep 6, 2025
Coinbase logo
Coinbase
Medium
Software Engineer

Implement banking ops: transfer, top-k, cashback, merge

Design and implement an in-memory banking system that supports: ( 1) CreateAccount(id, initialBalance) and Transfer(fromId, toId, amount) with validat...

Coding & Algorithms
15
0
132 people solved
Sep 6, 2025
Moveworks logo
Moveworks
Medium
Software Engineer

Select next Hangman letter

Given the current state of a Hangman game, implement a function that selects the next letter with the highest likelihood of appearing in the secret wo...

Coding & Algorithms
17
0
165 people solved
Sep 6, 2025
Motive logo
Motive
Medium
Software Engineer

Implement Union-Find and track components

Implement a Disjoint Set Union (Union-Find) data structure with union by rank and path compression. Design the API to support union(a, b), connected(a...

Coding & Algorithms
5
0
41 people solved
Sep 6, 2025
Rippling logo
Rippling
Medium
Software Engineer

Design a music player with favorites cap

Implement an in-memory music player that supports: addSong(id, metadata), removeSong(id), play(id), pause(), next(), prev(), getNowPlaying(), queueSon...

Coding & Algorithms
25
0
198 people solved
Sep 6, 2025
IBM logo
IBM
Medium
Software Engineer

Implement valid 1-D convolution with bias

Question Implement a "valid" 1-D convolution function in the cross-correlation sense. Given an input array of numbers, a kernel (filter) array of numb...

Coding & Algorithms
2
0
39 people solved
Sep 6, 2025
TikTok logo
TikTok
Medium
Software Engineer

Compute waits and find distance-k node pairs

Part 1 — Array next-higher wait: Given an integer array A where A[i] is the measurement for day i (0-indexed), return an array W of the same length su...

Coding & Algorithms
3
0
34 people solved
Sep 6, 2025
Pinterest logo
Pinterest
Medium
Software Engineer

Implement a min-heap column allocator

You are given an integer k (number of columns) and an array posts of positive integers where posts[i] is the height of the i-th post. All columns star...

Coding & Algorithms
22
0
187 people solved
Sep 6, 2025
Apple logo
Apple
Medium
Software Engineer

Design card deck with shuffle and order

Design a playing-card deck library with two methods: shuffle() to return a uniformly random permutation of a standard 52-card deck, and order() to ret...

Coding & Algorithms
3
0
68 people solved
Sep 6, 2025
TikTok logo
TikTok
Medium
Software Engineer

Design LRU cache with O(1) operations

Design and implement an in-memory cache that evicts the least recently used entry when capacity is reached. Support get(key) and put(key, value) in O(...

Coding & Algorithms
2
0
27 people solved
Sep 6, 2025
Meta logo
Meta
Medium
Software Engineer

Design an O(1) recency-evicting cache

Design and implement a fixed-capacity in-memory cache that supports get(key) and put(key, value) in average O( 1) time. When capacity is exceeded, evi...

Coding & Algorithms
7
0
99 people solved
Sep 6, 2025
Anthropic logo
Anthropic
Medium
Software Engineer

Design high-throughput hashing for kernels

Design a high-throughput hash-based lookup to be called inside a tight kernel. Choose between open addressing and chaining, specify the load factor, p...

Coding & Algorithms
17
0
179 people solved
Sep 6, 2025
Atlassian logo
Atlassian
Medium
Software Engineer

Implement snake game and find org LCA

Part A — Snake Game Engine: Implement a grid-based snake game. The board has height H and width W (0-indexed, row-major). The snake starts at (0, 0) m...

Coding & Algorithms
5
0
67 people solved
Sep 6, 2025
Anthropic logo
Anthropic
Medium
Software Engineer

Implement file deduplication at scale

Implement a command-line tool to find duplicate files in a directory tree. Use OS/pathlib primitives to recursively enumerate files. Apply prefilters ...

Coding & Algorithms
18
0
152 people solved
Sep 6, 2025
Uber logo
Uber
Medium
Software Engineer

Implement 2D word search variants and analyze complexity

Given an m x n grid of uppercase letters board and a string word, implement two related functions: ( 1) Fixed-direction search: Return true if word ap...

Coding & Algorithms
6
0
58 people solved
Sep 6, 2025

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