One job, many roles: The different skills needed to be a successful CTO
This is one thing I've seen crushing startups - not changing CTO's after traction, but keeping the founder that wrote the MVP as a CTO. It isn't always a bad thing, there are a lot of hackers that fill the role, but when it's not even considered because "he's a founder so he needs to remain CTO" vs "he's got the CTO skills" it is an alarming sign.I've worked in a startup (about 30 ppl)  where the CTO was one of the founders and he was doing nothing but holding the company back with his decisions and his 0-architecture-spaghetti code. My first day, when I saw all the trash going on I thought "ok I can't really quit my first day so they'll have to fire me".Decided to take ownership and start treating him like any other team member, reviewing and declining his merge requests (those weren't use before I came, they just commited all over the place), refactoring, planning ahead because otherwise we would have never delivered on time - his own technical debt extended feature delivery time by weeks. He was aware and admitted his "lack of skills", but wasn't aware of how much he actually lacked.We managed to take it out the gutter and polish it up a lot in the next two years, but after all the mess and his obvious lack of knowledge, he still remained the CTO, long  after I left. So please, if you are a CTO of a startup and are aware you lack skills, don't try to drive technical decisions and actively look for a replacement. Your decisions can create friction for whole company and burn it to ground right before it takes off. And if you work under a CTO like that, just take the damn responsibility and challenge dumb stuff or quit, or you might fall into the sloppy spaghetti.