3YoE
Position: ICT3 at Apple

1. Recruiter Screening : given 5 questions and asked to answer the questions and email back
   1. Passionate project
   2. How would you redesign it
   3. Favourite apple product
   4. Any performance issue you solved
   5. Experience on scaling applications
2. HM round :
   1. Explain previously project, what was your contribution to scale
   2. Warm-up find 1 missing number from 1ton digits and also what if there are 2 missing
   3. K sorted lists merge (why heap and why can’t hash map would work here)
   4. How would you redesign the message broker of any messaging service
3. Onsite 1 :
   1. Explain your project and walk through step by step with tech stack
   2. What is the size of the data that is generated by the application everyday
   3. What is the query per sec (QPS) of the application
   4. Coding question 1 : Subset sum possible or not
   5. Followup : print all the possible subsets with give sum
      1. Explain the time and space complexity of both the questions
4. Onsite 2 :
   1. Explain why do you want to join the company
   2. Coding question1 : given array of elements find the maxSpan got by any of the elements in O(n)
      1. What is the worst case complexity of HashMap
      2. What is Hashcode do return and what is equals method contract with Hashcode
   3. Coding question2 : car registers with classes and methods to get the value in O(1)
   4. What interests you to join the company
   5. Explain any situation where you solved the performance issue
5. Onsite 3 :
   1. What is your passionate project and have you faced any challenges
   2. Did you face any challenge in communicating with other teams? Or is it just within your team ?
   3. Coding question : decode a string 2[ab2[ca]], implemented through stack based approach
   4. Design question : tinyURL , how to you handle load and proper estimation by simulating it with the real world
6. Onsite 4 :
   1. What are the achievements you have, technical issues you solved
   2. Why do you want to join the company
   3. Design HashMap
   4. Why hash map has first linked list and then Balanced BST, after some threshold
   5. Draw a graph of time(Y) and put hashmap (X) axis with non-resizable hash
   6. Draw a graph of time(Y) and put hashmap (X) axis with resizable hash
   7. How do you resize the array list once they reach the load factor( == 1 then size == entries)
   8. What do you synchronize if put operations are performed and in parallel migration of data to new men location is all being done (sync, prev, next and current nodes in case of hm.remove())
7. Onsite 5 :
   1. Before graduation and after graduation what 3 things you learnt
   2. Product of values except self — given array, print product of subsets whose is length is n-1 (zeros count = 1 , >1 0 0 0 0)
   3. ABCD.….AA AB AC…. Get the values, similar to excel column number
   4. How do you implement BigInteger, addition subtraction, mul and division
   5. Multi threading singleton class implementation (volatile)
   6. How https://apple.com works
      1. What is s means
      2. What is 3 way handshaking of tcp ip
      3. Symmetric key encryption, public and private ke
8. Onsite 6:
   1. Get an element which is repeated twice
   2. Write a random generator to get random country from list, where the bias is towards the population of each country