I applied for a different position but was called for an interview for an embedded software engineer role.

I passed their home test (2.5 hours) and was then called in for an onsite interview.

I think they just use the home test to verify if you can write code, nothing more than that.

In the email, it was mentioned that I should check their products and get familiar with network techniques. I spent a few days on that.

On the onsite interview, there was actually a 1.5-hour coding test with a couple of coding questions. There was nothing tricky in their coding test; all basic textbook algorithms (sorting, searching, linked lists, pointer manipulation) but definitely needed muscle memory.

I was told my background was not a good fit at the very beginning of the interview. Then I got frustrated and performed pretty poorly during the interview process.

Given 1 billion numbers, find the median?