And to be frank, I've seen plenty of mission-critical services at $bigco which may have had a team of engineers working on them, but the core functionality was maintained, understood, and supported by effectively one senior engineer. If anything went wrong, the supporting junior staff might have been able to fix reasonably simple stuff, but there was essentially one person who understood the system deeply enough to handle problems of any real significance.
Early in my career, I became the second person able to support and operate a system that was public facing and responsible for billions of dollars of activity that mattered to many individuals and stakeholders. The entire team retired over a period of six months, after giving the folks in charge a year or more notice. After about 12 weeks, I was the sole guy, training a 4-5 new people.
We’re all probably using a service like this. As demonstrated by Twitter, well engineered systems can persist, even without proper care and feeding, until they don’t.
