Paytm Interview Experience for Senior Software Engineer | 4 Years Experienced Last Updated : 16 Jun, 2021 Improve Improve Like Article Like Save Share Report Technical Round(1 hr): Asked about my current company projects and techstack used what is thread? Synchronized keyword? Diff. ways of creating threads in java, which one is better? difference b/w multithreading & multiprogramming What is txn in DBMS? ACID properties Internal implementation of map. How put of HashMap works? https://www.javatpoint.com/working-of-hashmap-in-java Reverse singly linked list. Also write recursive code (https://www.geeksforgeeks.org/recursively-reversing-a-linked-list-a-simple-implementation/) https://www.geeksforgeeks.org/detect-and-remove-loop-in-a-linked-list/ https://www.geeksforgeeks.org/sort-an-array-of-0s-1s-and-2s/ https://www.geeksforgeeks.org/design-a-stack-that-supports-getmin-in-o1-time-and-o1-extra-space/ Write code for singleton class and make it thread safe. Technical Round(1 hr): What is inheritance? Give an example Function overloading and overriding Static func. related question Java class MyBase{ public static void func(){ System.out.println("Base static called"); } } class MyDerived extends MyBase{ public void func(){ // is this allowed? System.out.println("Derived static called"); } } SOLID principles HashMap and HashSet in java. How they work? How Garbage Collector works? When it is called and how can we call it explicitly? (https://www.tutorialspoint.com/how-can-we-call-garbage-collection-gc-explicitly-in-java) https://www.geeksforgeeks.org/minimum-cost-to-reach-from-the-top-left-to-the-bottom-right-corner-of-a-matrix/ Which design patterns are used by you? Explain observer pattern. Also, Tell scenario where Singleton pattern was used in your project. https://www.geeksforgeeks.org/maximum-size-rectangle-binary-sub-matrix-1s/ Difference b/w abstract class and interface. Why both are required? Can abstract class have constructors? How can we make a variable immutable in java? Is it possible to modify final variable value? Technical Round(1 hr): Adv. and disadv. of indexing A db Table having 100 Million rows, A B C are 3 columns A -> 1000 Unique values B -> 1 Million Unique Values C -> 10 Million Unique Values query made oftenly on db-> “select * from T where A = ? and B = ? and C = ?” How we should create indexes in the table? Can’t we create composite indexes on A,B? Isolation levels in SQL. Public key, private key, cryptography. Diff b/w MongoDB and SQL HAshMap put() and get() complexity Time complexity of following code: Java int fib(int n) { if (n == 0 || n == 1) { return n; } return fib(n-1) + fib(n-2); } https://www.geeksforgeeks.org/maximize-sum-of-k-elements-in-array-by-taking-only-corner-elements/ What are features of spring and spring boot? Do you know about Redis? what is HTTP and HTTPS? Like Article Suggest improvement Previous TechMahindra Interview Experience for CoE Next Avaya Internship Interview Experience 2021 Share your thoughts in the comments Add Your Comment Please Login to comment...