I’ve recently been working with a few folks looking to start out in coding/development careers. Quite a few entry-level positions seem to be filtered by programming tests. I won’t go into my feeling on these, as personally, I’m not a huge fan of this approach. As an employer, I was always more interested in the individual’s character and approach to problem-solving as opposed to a pressured machine judged pass/fail.
However, with that said, these styles of testing have become more common. They perform many of these tests in web-based environments. So it’s worth becoming familiar with the tools available. https://leetcode.com/ is a good example of a tool used. It is worth getting familiar with these environments. It has a significant number of exercises, they are a bit recursion biased (from my samples) but can give you a good idea of what to expect.