Senior Software Engineer at J.P. Morgan

How it went

What they would tell you

How to prepare

Round by round

1. 1

   Technical Round 190 min

   Interviewer was very professional, started with friendly introduction The interviewer started with some Java questions. She wanted to know if I really understood Java 8, not just used it. She asked, “What are the main features of Java 8?” I talked about lambdas, streams, the new Date/Time API and default methods in interfaces. Then she asked, “What is a functional interface?” I said it’s an interface with only one abstract method like Runnable or Comparator. She wanted examples: I gave Runnable (for threading), Comparator (for sorting), and Predicate (for filtering).

   Coding Question Then came the coding part. Find the repeating and missing number in an array of size N containing numbers 1 to N. I wrote the code using a frequency map (or a boolean array), then iterated to find which number is missing and which is repeated.

   SQL Question She also asked a SQL question, something about joining two tables and counting certain records. I wrote the query, explained why I used a LEFT JOIN, and how I’d optimize it if the table grew. And some window function ,here i lack.

   • Find the repeating and missing number

What came up