What counts as boring? That’s a little tricky. “Boring” should not be conflated with “bad.” There is technology out there that is both boring and bad. You should not use any of that. But there are many choices of technology that are boring and good, or at least good enough. MySQL is boring. Postgres is boring. PHP is boring. Python is boring. Memcached is boring. Squid is boring. Cron is boring.
The nice thing about boringness (so constrained) is that the capabilities of these things are well understood. But more importantly, their failure modes are well understood.
He goes on to explain the process you should go through before you try out a new technology.