Visa Inc. Senior Software Developer interview questions

General question of Java, programming, lambda, solve Hackerrank questions.

1. There is a hacker rank test for 60 minutes Link provided by the time of 1st round live screen share with hr taking screenshot for govt id proof. Test has a 8 question in that 5 are mcqs and 2 are coding and 1 is SQL query. 2. Flatten Array https://stackoverflow.com/questions/31851548/flatten-nested-arrays-in-java 3. Given [1,2,3,4,5,6,7,8,9, 10] , K=3 output : [1,2,3] [4,5,6] [7,8,9], [10] 3rd round 1, convert a string from snake case to camel case and vice versa. 2. Can we keep a class as a key in the hashmap. 3. If yes what needs to be done ( change the class to immutable) 4. Please read overiding equals and hashcode method thoroughly 5. Design a file system and search the file Final Round Director round 1. Design message reading mechanism -> Message can pass from publisher to subscriber in any order but we need to read the message in a particular a sequence only. 2. Given a digital time example: 12:30 -> Write a program to return the angle between the minute hand and hour hand is acute(<90 degree) or obtuse(more than 90 degree) if you imagine it in a analog watch. 3. Given a small code snippet asked me the output ? 4. What challenges you faced.