BOJ (Baekjoon Online Judge), a big competitive programming site in Korea, says it's shutting down on April 28. It has been around since 2010 and, as far as I know, has mostly been one person's work the whole time. The notice doesn't say why. The rumor is that the server bills finally got too high.

What caught my eye is that some people in the Korean #fediverse, including @2chanhaeng, are already talking about whether a federated replacement could work, with #ActivityPub coordinating things and volunteer nodes doing the judging. I have no idea if that can really work, since timing differences between machines are a serious problem in competitive programming, and I'm not the right person to help with it. Still, I like that the first reaction was to try building something.