I did two interviews for this rather-small agency in the U.S. Both were more on the discovery and talk-about-yourself side - both went great, really connected with both interviewers - but at the end of the second one I was sent an assignment to solve rather than a technical interview. I did it, sent it, and went back and forth as they were having problems with the files. After everything was delivered I was thanked and told to wait for an update. After a week and a half of radio silence, I sent a follow-up and they let me know they've been busy and hadn't had the time to review my assignment, but that they were going to keep me posted "hopefully" during the week. It's been two weeks since then and I feel I should send another follow-up as there hasn't been any news in the timeframe I was given.
I know I should probably wait another two weeks - Holidays were one of the reasons they've been so busy, with everyone going on vacation. The thing is I'm completely lost on how to follow up as most examples and blogs I find online are not very specific to my case (unreviewed assignment). I would love to hear some opinions or ideas from people with more experience in the interview process, as this is something I struggle with.