For 1 I guess it also boils down to the mindset you approach a problem. On my past companies when you have a problem the first thing you do is to find a OSS or product that solves that for you and even when you don't find you try to reframe the problem in a way that will fit that solution that you already have in your mind, at google it normally involves on you solving that by yourself or reusing much lower level of abstractions.
This doesn't mean that you will need to always create your own database, but when you really need to you have the skills to do a decent job.
For 1 I guess it also boils down to the mindset you approach a problem. On my past companies when you have a problem the first thing you do is to find a OSS or product that solves that for you and even when you don't find you try to reframe the problem in a way that will fit that solution that you already have in your mind, at google it normally involves on you solving that by yourself or reusing much lower level of abstractions.
This doesn't mean that you will need to always create your own database, but when you really need to you have the skills to do a decent job.