דואגים שתהיו מוכנים: מאגר ענק ומעודכן של שאלות בראיון עבודה הייטק

במקום לתת לכם להמשיך לשבור את הראש, לגגל "שאלות ראיון עבודה הייטק" ולקושש שאלות מעשרות כתבות שונות, חלקן ישנות וכבר לא רלוונטיות, החלטנו לעשות את העבודה בשבילכם - לרכז את כל השאלות הכי נפוצות ממבחנים בראיונות עבודה להייטק באנגלית, ברשימה אחת מלאה ומעודכנת לשנת 2020.

לצורך הרכבת הרשימה אספנו שאלות מראיונות עבודה פרונטליים בהייטק בשלבי מיון שונים, שאלות ממבחנים בהייטק וגם שאלות ממבחני בית בהייטק. נעזרנו בטאלנטים שלנו ובקשרים שלנו עם מיטב החברות בארץ על מנת לקבל רשימה אמיתית של כל השאלות הכי פופולריות, הכי חשובות, הכי קשות והכי אהובות על המגייסים, היישר מתהליכי המיון של מיטב החברות והסטרטאפים.

מה תמצאו כאן?

- רשימת שאלות כלליות שחוזרות על עצמן ברוב ראיונות העבודה להייטק, החל מקבלת אינפורמציה על פרויקטים שהייתם שותפים להם בעבר ועד למושגי קוד בסיסיים

- רשימת שאלות שעוסקות בפתרון בעיות ואלגוריתמים ובוחנות בעיקר לוגיקה, יצירתיות וחשיבה מחוץ לקופסה

- שאלות נוספות מחולקות לפי סוגים, בהתאם לתחום העבודה, אשר מאפשרות למראיין לבחון את הבקיאות שלכם בשפות הפיתוח ובסביבות העבודה הנדרשות עבור התפקיד.
תמצאו כאן למשל רשימה אמיתית של שאלות מראיון עבודה full stack, שאלות מראיונות עבודה C#, שאלות למועמדים מתחום הסייבר, חומרה ועוד

באמצעות הרשימה תוכלו להבין מה מצופה מכם, להיזכר בפרטים הקטנים שכבר שכחתם, לאמן את תאי המוח ולהגיע לראיון כשאתם מוכנים ומלאי ביטחון. נכון, את התשובות תצטרכו להבין בעצמכם, אבל מניסיוננו – זו הדרך הטובה ביותר להתכונן לראיון, להשאיר את הרושם הרצוי ולמקסם את סיכויי הקבלה לעבודה. 

Dear candidate,
We have gathered for you a list of real questions from tests and recruitment processes in high-tech companies and leading startups.

Every month we help thousands of high-tech talents successfully go through the recruitment process by properly preparing them for the questions they will ask - this is a key step that helps our candidates go through the process successfully.
Feel free to go over the questions by your area of expertise and practice.
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| General Questions 

1. Every single question from "cracking the code interview"
2. Tell us a project or major feature you made or lead
3. In SQL

a. What’s the difference between Delete and Truncate & Drop?
b. Left inner join
c. What’s the difference between where and having, left join vs inner join

4. Microsoft Process vs Thread
5. Explain http - get / put / post / delete
6. How does GC (Garbage Collector) works?
7. Describe the protocol from layer2 in http packet
8. Interface vs abstract class
9. Explain cache logic LRU/LFU/MRU…
10.Array vs Dictionary
11.What are the mandatory fields in http request header?

 Problem solving & algorithms Questions |

1. Implement Fibonacci sequence
2. Given 2 int arrays of sizes n & k – provide an algorithm to find the minimum differences between the numbers
3. Find all Prime numbers from 0 to a given X
4. Let’s play ‘7 Boom’ - Implement a series of numbers from 0 to a given X that all its numbers either divided by ‘7’ or contains ‘7
5. Given a 2D array that represents a maze, and you're starting in a certain position, find out if the maze has an exit or not (tip – the answer requires correct 'if' conditions, preventing infinite loops)
6. Build a script that given a site, collects all the links from the site - and all the links from all those links. Prevent infinite loops, use horizontal scaling in order to allow for better performance given a high amount of links. Design-wise.

7. Linked Lists

 a. Provide a method to remove one node from a linked list
 b. Provide a method to add one node to a linked list (start/middle/end)
 c. Provide a method to search a certain node in a linked lista.
 d. Provide a method to Transpose a linked list
 e. What’s the time complexity of the above methods?

8. Given an integer array – print all possible permutations

9. Write a ‘Hangman’ solver as efficient as possible.

10. Given a sorted array of unique numbers, find the *k*th missing number starting from the leftmost number of the array

11. Binary Tree
  a. Given a binary tree, write a method that will get the tree root as input and will return true if the tree is a Full (Proper) Binary Tree
  b. Reassemble a tree with in-order and pre-order list
  c. Can you get to any node at a binary tree in O(log(n))?

12. Transpose a string (character array)

13. Find node ‘x’ in n-sized array (what’s the best time complexity performance) 

14. Implement a certain state machine

15. Parse a large csv file without loading it into memory

16. Write a method in C to allocate and free RAM that uses malloc and free and returns memory blocks aligned to 16 bits.

17. All kind of concurrency problems and solutions…

18. Given an array of numbers arr and a number x - Find if there are two numbers: a, b in arr such that a + b = x.
* Find without using additional memory

19. Write an algorithm that generates a random number in a given range (min & max limits)

20. Find the index of a given numeric value at a sorted array

21. Given a matrix of values (0/1) that represents a maze:

   0 - represents a path   
   1 - represents a wall

Write a method that receives 2 locations at the maze and checks if there’s a path between them.

22. Write an event-loop class that exposes subscribe on a certain event and trigger this event.

23. Given malloc2 & free2 that get also an address, how would you implement malloc & free?

24. Write a program that gets N x N matrix and at each cell with ‘0’ it clears the row & column of this cell

25. Given a sorted array find the count of duplicates

26. Given Redis API get counter of current process with start and stop events in O(n) and O(1)

27. Write a program that gets an odd number as an input and draws ‘X’ using ‘*’ on the screen (console) – (time limit to solve this question – 15 min)

28. Given a string and dictionary of words, devide the string to a sequence of legal words from the dictionary.
Example:
  ● Dictionary: {ice, coffee)
  ● Input string: ‘icecoffee’
  ● Output: ‘ice’, ‘coffee’
  ● Input: ‘icecicecoffee’
  ● Output: none

29. Hash table:
  a. What’s the time complexity of add & delete?
  b. Transform a linked list to hash-table

30. Write a program that keeps getting numbers and returns the median of all given numbers.

31. Write a program with input of 4 digits and returns the latest legal hour they can represent.

32. Given an array with tuples – each tuple represents start & end time of a meeting, each meeting needs a conference room and each conference room can obtain only one meeting at a time.
Write a program that gets the array and returns the minimal number of conference rooms required to hold all the given meetings.

33. Given an array of strings, implement a function that returns the lowest common prefix

34. Write a function that gets a string & position of 2 random words in this string and replaces the locations of these 2 words. (focus on time & memory complexity)

35. Given a sorted array of unique numbers, find the *k* -th missing number starting from the leftmost number of the array.

36. Write an algorithm that given stock values over time calculates the maximum profit you could achieve by buying and selling at a given time.

37. You’re playing against your PC. On the table there are k coins with different values from -∞ to ∞. At each turn you should select a coin from right or left so that once all coins are finished the sum will be either equal or higher than the PC. The PC will always pick the coin with the higher value from both sides * you can scan the array initially but you can’t change its order.
* can be done at O(n)

38. Write a data structure that can provide the following functionalities:
  a. Retrieve a value by a given ‘name; (get)
  b. Set a value for a given ‘name; (set)
  c. Set one value for all fields; (set_all)

* All functions should be at time complexity - O(n)

| Backend / Frontend / Full-Stack / Mobile

1. Explain dependency injection – where did you use it?

2. what is immutable?

3. What is currying?

4. What is Pure Function?

5. What’s the difference between let & var?

6. What is Angular Semantics?

7. What is Observable and RxJs?

8. How redux works under the hood?

9. What the difference between arrow function to regular function

10. What is "this" in JS?

11. What the difference between bind and call

12. What is the difference between regular function and Fat arrow function? (JS)

13. What is closure?

14. Implement a promise (JS)

15. In JS – what’s the best way to add a functionality to a constructor function without changing its code?
*Answer: prototype keyword funcName.prototype.newFunc = function()...

16. How do you pass values to a component?

17. What is lazy loading?

18. What is the difference between filter find and map?

19. How are classes implemented (vtable)?

20. Explain: Closure, prototyping, ES5, ES6, ES7, Promise/async/await, Virtual DOM

21. iOS – what is AppDelegate life cycle

22. What is a bean in spring boot?