I have been in a similar situation. After applying to a code bootcamp and completing the assigned challenges I was invited in to take a coding challenge. The student of the camp who gave me the challenge was very vague and hard to read. I had been studying that programming language for months and knew it inside and out but was nervous about the interview and didn’t know how to translate my knowledge into the answer he was asking for. It was frustrating, I had already built a number of little web programs, like games and productivity apps, and I had gone above and beyond on my assignments, but the interview/code challenge didn’t give me any way to demonstrate the value I had to offer. Weeks later I met some students from the program at a coding event and found that they hadn’t learned or done nearly as much as I had but still made it into the program.
In short, I have also been through the experience of going through an interview and feeling like I wasn’t able to effectively communicate all that I had to offer. This idea of doing a project to pre-qualify yourself could have potentially helped me get int the program had I thought of it at the time. Even just the idea of making a case for yourself in the follow up is helpful. When I was starting out, such an idea seemed out-of-bounds.
Thanks for writing this and sharing, it may be a big help to me or others in the future. At the very least it changes my view of the whole interview process and gives me ideas on how to make it less of a shot in the dark.