Twilio is an American company based in San Francisco, California, which provides programmable communication tools for making and receiving phone calls, sending and receiving text messages, and performing other communication functions using its web service APIs.

It has got a 4.3* rating on Glassdoor and is considered one of the best product-based companies. It is highly regarded for its work-life balance.

They provide good training as well which will be beneficial in future too. You can practice the below questions collected from Twilio Interview Experience for the interview. We have collected past frequently asked questions from Twilio Interview Experience for your reference.

Categories of Questions

## Twilio Array Questions

**Question 1. Sort Array by Increasing Frequency Leetcode Solution** Problem Statement The Sort Array by Increasing Frequency LeetCode Solution – “Sort Array by Increasing Frequency” states that you’re given an array of integers, sort the array in increasing order based on the frequency of the values. Two or more values have the same frequency, we need to sort them ...

**Question 2. Sort Array by Increasing Frequency Leetcode Solution** Problem Statement Given an array of integers nums, sort the array in increasing order based on the frequency of the values. If multiple values have the same frequency, sort them in decreasing order. Example nums = [1,1,2,2,2,3] [3,1,1,2,2,2] Explanation: ‘3’ has a frequency of 1, ‘1’ has a frequency of ...

**Question 3. Sqrt (or Square Root) Decomposition Technique** You are given query of range an integer array. You will be asked to determine the sum of all the numbers that come in the range of given query. The query given is of two types, that are – Update: (index, value) is given as a query, where you need ...

**Question 4. Check if two arrays are equal or not** The problem “Check if two arrays are equal or not” states that you are given two arrays. The problem statement says that you have to determine if given arrays are equal or not. Example arr1[] = { 1, 4, 2, 5, 2 }; arr2[] = { 2, 1, 5, 4, ...

**Question 5. Generate all possible sorted arrays from alternate elements of two given sorted arrays** The problem “Generate all possible sorted arrays from alternate elements of two given sorted arrays” states that suppose you have two sorted arrays. The problem statement asks to find out all the possible sorted arrays, such that number should be arranged alternatively from the two given different arrays. Example ArrA[] ...

**Question 6. Range sum queries without updates** Problem Statement The problem “Range sum queries without updates” states that you have an array of integers and a range. The problem statement asks to find out the sum of all the elements within the given range. Example arr[]={10, 9, 8, 7, 6} Query: {(0, 4), (1, 3)} 40 24 ...

**Question 7. Three way partitioning of an array around a given range** Problem Statement You are given an array of integers and a range of lowValue and highValue. The problem “Three way partitioning of an array around a given range” asks to partition the array such that array will be divided into three parts. The partitions of the arrays will be: Elements ...

**Question 8. Sum of minimum and maximum elements of all subarrays of size k** Problem Statement The problem “Sum of minimum and maximum elements of all subarrays of size k” states that you are given an array containing positive and negative integers, find the sum of minimum and maximum elements of all the sub-arrays of size k. Examples arr[] = {5, 9, 8, 3, ...

**Question 9. Move all negative elements to end in order with extra space allowed** Problem Statement “Move all negative elements to end in order with extra space allowed” states that you are given an array containing positive and negative numbers both. The problem statement asks to move all the negative elements in the last of the array. Example arr[] = { 1,2,-3,-5,2,7,-9,-11 } 1, ...

**Question 10. Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest** Problem Statement Suppose you have an integer array. The problem “Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest, ..” asks to rearrange the array in such a way that the smallest number comes first and then the largest number, then second smallest and then the second ...

**Question 11. Printing brackets in Matrix Chain Multiplication Problem** Problem Statement We need to find the order of multiplication of matrices such that the number of operations involved in the multiplication of all the matrices is minimized. Then we need to print this order i.e. printing brackets in matrix chain multiplication problem. Consider you have 3 matrices A, B, ...

**Question 12. Find Three Element From Different Three Arrays Such That a + b + c = sum** Three Sum is a problem loved by interviewers. It is a problem I was personally asked during the Amazon interview. So, without wasting any more time let us get to the problem. An array that has both positive and negative numbers. Three numbers that sum up to zero/can be modified, ...

**Question 13. Subarray Sum Equals k** Given an integer array and an integer k. Find total number of contiguous subarrays of given array whose sum of elements is equal to k. Example Input 1: arr[] = {5,0,5,10,3,2,-15,4} k = 5 Output: 7 Input 2: arr[] = {1,1,1,2,4,-2} k = 2 Output: 4 Explanation : consider example-1 ...

**Question 14. Subarray with Given Sum** Problem Statement In the subarray with the given sum problem, we have given an array containing n positive elements. We have to find the subarray in which the sum of all the elements of the subarray equal to a given_sum. Subarray is obtained from the original array by deleting some ...

**Question 15. Find All Pairs With a Given Difference** Problem Statement We have given an array of containing different elements or no repeated elements present in the array. Find all pairs with a given difference. If there is no any pair with given different then print “No pair with given different”. Example Input 10 20 90 70 20 80 ...

## Twilio String Questions

**Question 16. Letter Combinations of a Phone Number** In letter combinations of a phone number problem, we have given a string containing numbers from 2 to 9. The problem is to find all the possible combinations that could be represented by that number if every number has some letters assigned to it. The assignment of the number is ...

**Question 17. Count Substrings with equal number of 0s, 1s and 2s** The problem “Count Substrings with equal number of 0s, 1s and 2s” states that you are given a string that has 0, 1, and 2 only. The problem statement asks to find out the number of substrings that contain equal no of 0, 1, and 2 only. Example str= “01200” ...

**Question 18. Text Justification LeetCode Solution** We will discuss Text Justification LeetCode Solution today Problem Statement The problem “Text Justification” states that you are given a list s[ ] of type string of size n and an integer size. Justify the text such that each line of text consists of size number of characters. You can ...

## Twilio Queue Questions

**Question 19. Sum of minimum and maximum elements of all subarrays of size k** Problem Statement The problem “Sum of minimum and maximum elements of all subarrays of size k” states that you are given an array containing positive and negative integers, find the sum of minimum and maximum elements of all the sub-arrays of size k. Examples arr[] = {5, 9, 8, 3, ...

## Twilio Matrix Questions

**Question 20. Printing brackets in Matrix Chain Multiplication Problem** Problem Statement We need to find the order of multiplication of matrices such that the number of operations involved in the multiplication of all the matrices is minimized. Then we need to print this order i.e. printing brackets in matrix chain multiplication problem. Consider you have 3 matrices A, B, ...

## Twilio Other Questions

**Question 21. Sliding Window Maximum LeetCode Solution** Problem Statement Sliding Window Maximum LeetCode Solution Says that – You are given an array of integers nums, and there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time ...

**Question 22. Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution** Problem Statement Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution – Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution says that – You are given a list of songs where the ith song has a duration of time[i] seconds. Return the number of pairs of songs for which ...

**Question 23. LRU Cache Leetcode Solution** Problem Statement The LRU Cache LeetCode Solution – “LRU Cache” asks you to design a data structure that follows Least Recently Used (LRU) Cache We need to implement LRUCache class that has the following functions: LRUCache(int capacity): Initializes the LRU cache with positive size capacity. int get(int key): Return the value ...

**Question 24. Find Median from Data Stream LeetCode Solution** Problem Statement Find Median from Data Stream LeetCode Solution – The median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value and the median is the mean of the two middle values. For example, for arr = [2,3,4], the median ...

**Question 25. Reformat Date LeetCode Solution** Problem Statement Reformat Date LeetCode Solution – Given a date string in the form Day Month Year, where: Day is in the set {"1st", "2nd", "3rd", "4th", ..., "30th", "31st"}. Month is in the set {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}. Year is in the range [1900, 2100]. Convert the date string ...

**Question 26. Subarray Sum Equals K LeetCode Solution** Problem Statement The Subarray Sum Equals K LeetCode Solution – “Subarray Sum Equals K” states that you are given an array of integers “nums” and an integer ‘k’, return the total number of continuous subarrays whose sum equals to ‘k’. Example: nums = [1, 2, 3], k=3 2 Explanation: There ...

**Question 27. LRU Cache LeetCode Solution** Question Design a data structure that follows the constraints of a Least Recently Used (LRU) cache. Implement the LRUCache class: LRUCache(int capacity) Initialize the LRU cache with positive size capacity. int get(int key) Return the value of the key if the key exists, otherwise return -1. void put(int key, int value) Update the value of the key if the key exists. Otherwise, add the key-value pair to ...

**Question 28. LRU Cache Implementation** Least Recently Used (LRU) Cache is a type of method which is used to maintain the data such that the time required to use the data is the minimum possible. LRU algorithm used when the cache is full. We remove the least recently used data from the cache memory of ...

**Question 29. Find Pair with Given Difference** Problem Statement In the given unsorted array, find the pair of elements in the given array with given difference n. Example Input arr[] = {120, 30, 70, 20, 5, 6}, difference(n) = 40 Output [30, 70] Explanation Here the difference of 30 and 70 is equal to the value of ...