OPSWAT interview questions

Applied online. Get a offline assessment. Two coding questions. One is straight forward and another one is related to sorting application. You need to test the code on your own machine and email them your solution. Get followup response a month later to setup a onsite interview. There are 3 rounds F2F. First round is just chatting, Topic on your experience and your understanding on security product. Second round is about language basics and a coding question. Third round is unit testing.