From a tools/infrastructure support perspective, standardizing on tools and clearly declaring and assigning a single tool for each function. Clearly ask people to pitch in to adhere to this. Set clear standards for yourselves.
From a people perspective, clearly defining goals and constantly asking clarity questions to gauge if there is alignment is the only real way. Also if you notice people are not aligned but they think they are, declare that you're not sure they're aligned. They'll hash it out themselves.
It also helps for people to declare when they're unavailable in something like a slack channel. Finding out someone is not there when you expect the to be is very jarring/frustrating.
You are a technologist with hands on business/startup experience.
This is unbelievably valuable especially in leadership positions. Especially in the case if your startup wasn't just you.
A lot of this also depends on what you are looking for as well. From your statements you may be thinking looking for a job as an Engineer which is great if it is what you want to do.
I believe you have other options if taking a job as an Engineer does not sound ideal to you.
Unfortunately, the reason they probably chose their own solution is that it was probably the easiest way to get it into production in a repeatable way in their mind with the least risk they would mess it up.
By now, I think fizzbuzz has been around enough that people know it, have heard of it, and prepare enough to solve it.
I have started using variations of fizzbuzz or additional questions that builds on it and I find myself catching people who only know the fizzbuzz portion.
Definitely not generating income at your level and so probably why there's a bigger need for a plan on my end. The risk/high reward advice makes a lot of sense. Sometimes it probably is just the way you view it.
The financial aspect is definitely something that I've been saving up and working towards for a long time now. The path of transition is really what's not clear in my head. Your advice on the investment of my family is a good point.
From a people perspective, clearly defining goals and constantly asking clarity questions to gauge if there is alignment is the only real way. Also if you notice people are not aligned but they think they are, declare that you're not sure they're aligned. They'll hash it out themselves.
It also helps for people to declare when they're unavailable in something like a slack channel. Finding out someone is not there when you expect the to be is very jarring/frustrating.