Broadcast a message to all participants at any time.

It'd be nice to have this option in case both parties agree to record so we can replay during debrief

A good developer can performs a fast solution. If exists some questions that check the execution time and compare it with a expected time, this will be so good to know if the developer knows the fastest algorithms. Another suggestion is to verify the algorithm complexity. Thus, if the question expected a solution O(1) but the developer solved using a O(n) for example, then it will be useful to check the develoler knowledge.

I would like to have an option to edit like I am in vim. Minimal options are fine, but navigation and selections are easier for me in vim style editing.

Add c++ 17 support. It adds many new features. Also update versions of other programming languages (if applicable).

Add intelligent API suggestions to your IDE similar to how https://repl.it/languages/java10 works.

Add more questions that cover a variety of programming skills.

It would be really helpful if we were able to get alerted to potential plagiarism in both RI and CodeInterview. In a live coding challenge, detecting the plagiarism in real-time and getting a link to the site where it was found would be extra helpful so we could ask some targeted follow up questions. On the one hand, I expect developers to use the internet both during a code challenge and in their day job. On the other hand, a copied solution often isn't well understood, so getting feedback that the code might be plagiarized could allow the interviewer to ask probing questions to make sure the candidate actually understands the solution.