not recent projects but everything that DJB implemented is absolutely elegant, low on bugs and great as a lesson for how to write secure C. e.g. qmail, djbdns, daemontools, there is a lot of ideas there you can learn from: https://cr.yp.to/
It also helps to build up (and refactor) your toolset over time, memory handling wrappers, logging, I/O, daemonize (https://github.com/jirihnidek/daemon) etc, so that you don't have to keep reinventing the wheel.